Introduction to IT - D322 Flashcards
Information Technology
The technology used in creating, maintaining, and making information accessible.
IT Professional Roles
Administration and Support
System Administrator
Maintains all aspects of the system including hardware, software, and programming.
Network Administrator
In charge of all aspects of the computer network
Database Administrator
Focuses on the design, development, and support of database management systems (DBMSs).
Security Administrator
Installs, configures, and administers firewall security to protect systems and proactively work to stop intrusions.
Web Administrator
Installs, configures, maintains, secures, and troubleshoots web severs.
Support IT Professionals
Help desk and training.
Information
Processed data.
DIKW Hierarchy
Defines the transition of data to information from knowledge to wisdom. (Data Information Knowledge Wisdom)
Data in DIKW
The input directly received by the user (or computer). It is generally not usable until it has been converted into a relevant form.
Information in DIKW
Having been inferred from data; one or more processes have been applied to the data to transform it into a more useful form.
Knowledge in DIKW
Information that has been put to use; information placed into a context. Refined information such that the user of the knowledge is able to call forth only relevant portions of information when needed.
Wisdom in DIKW
Provides a social setting to knowledge; an understanding of the “why”. Can only come by having both knowledge and experience.
Information Systems
A collection of data and information used to support the management of an organization. Also refers to the technical components and human resources that enable the assembly, storage, and processing of data and the delivery of information. This has existed for a lot longer than computers.
Characteristics of Quality Data
Relevance - the data being used must apply directly to the decision being made
Timely - data must be efficient and must be provided in a timely manner
Thorough - the data must be complete
Accurate - data should be captured only once, where possible and should be captured as close to the point of activity as possible.
Reliable - data should reflect stable and consistent data collection processes across collections points and over time
IPOS
The Input-Procession-Output-Storage Cycle
Input
Raw data is entered by the user.
Processing
Raw data is organized or structured for usefulness.
Output
Information is output so user can see results.
Storage
Processed information is stored for permanent record.
Computer System
A collection of components that work together to meet the needs of the user; typically categorized as either hardware, software, networks, or users.
Hardware
Physical components of a computer system which include the system unit and its components and peripheral devices; tangible aspects of the computer.
Software
Computer programs that tell the computer what to do–how to execute commands and process information
Network
A collection of computers and resources connected by various media so that they can communicate with each other.
User
Those who use a computer.
Software Categories
Systems Software and Applications Software
Evolution of Users
First users were the engineers who built and programmed computers, then employees who had received specialized training were users, and now today, anyone and everyone can be a user.
Protocol
Rules provided by which networks communicate with each other.
TCP/IP
Transmission Control Protocol/Internet Protocol. Most commonly used protocol; is required of all computers that communicate over the Internet.
Protocol Stack
A collection of protocols. TCP/IP is an example.
Components of a Computer
CPU, Memory and Storage, Peripheral Devices
CPU
Executes programs’ instructions and commands various components in the computer. Referred to as the “chip”.
Memory
Stores the programs being executed and the data they are using.
I/O Subsystem
All peripheral devices where long term storage devices are used
Bus
Permits information to move between each component; electrical channels that enable communication among the electronic components
System Unit
Critical component of all computer based systems; consists of most of the hardware the computer needs in order to run; comes in a variety of shapes and sizes.
Internal Components of the System Unit
Case, Internal Bays, Buses, Ports, Hard Drive, Motherboard, CPU, CPU Cooler, Memory Module (RAM), Power Supply Unit (PSU), Expansion Slots/Cards
Parts of the CPU
Control Unit (CU) - retrieves the instructions and the raw data that is input and coordinates or controls the sending of those instructions and data to the ALU
Arithmetic Logic Unit (ALU) - does the actual processing of the data; completing mathematical calculations and logical operations to process the data and converting the input of the keyboard text entry to output displayed on the screen
System Clock
Controls the speed at which instructions are processed.
RAM
Stands for Random Access Memory.
It temporarily stores data before it is processed and sent to your screen or printer.
It is volatile (means data or information stored disappears when the computer is turned off or loses power).
You can choose the amount of RAM your computer has.
Types of RAM
Dynamic RAM (DRAM) - typically called main memory
Static RAM (SRAM) - cache memory and registers
BIOS ROM
BIOS stands for Basic Input Output System; ROM stands for Read Only Memory.
Typically stored in ROM chip on the motherboard.
Is software not hardware, (“basic” operating system that runs when the computer is first turned on).
Runs tests of memory and the CPU and initializes hardware components so that the actual Operating System can be loaded from the hard disk.
Can’t choose the amount or contents.
1st Generation of Computers
Vacuum tubes, relay switches, the need to program in machine language
2nd Generation of Computers
Transistor components, magnetic core memory, smaller size, easier to program, disk drives and drums, called mainframe computers
3rd Generation of Computers
Silicon chips (known as ICs - integrated circuits), reduced cost, called mini computers, networks introduced via dumb terminals
4th Generation of Computers
Single chip processor, called microcomputer, first personal computer, rudimentary computer graphics, home use
Moore’s Law
Doubling of transistor count roughly every 18 - 24 months (exponential increase)
Evolution of Storage
Punch cards, magnetic tape, hard disks, floppy disks, optical discs, flash memory, cloud storage
Machine/Low-level Language
Written for a specific machine by the engineers who built and ran the computers; no need for OS since only one program could run at a time
Assembly Language
Easier than machine but still required detailed, precise low level instructions
Language Translator Programs
Function is to translate one program language into another; take source code and convert it to another form; source code by itself cannot be read by a computer
Compiler
Improve language translator; requires that the components of the software all be defined before compilation can begin; code is more effcient
Structured Programming
Programmer is limited to high level control constructs such as while loops, for loops, and if/else statements and not allowed to use primitive GOTO statements
Object Oriented Programming
Characterized by the creation of windowed operating systems, easier real-world object modeling in programming code, and the application of inheritance in program code.
Interpreted Code
A type of programming language for which most of its implementations execute instructions directly and freely, without previously compiling a program into machine-language instructions.
Shell Scripting
Small programs that place Linux commands or DOS batch files into a file
Local Computer
The computer that the user is using; physically present with
Remote Computer
A computer being accessed over the network
Network Hub
Connects computers to each other with no real understanding of what is being transferred; used for private networks with local computers.
Network Switch
Like a hub, but this will only send data that is intended for a specific computer.
Router
Connects multiple networks together; can be used to directly connect computers to a network; will relay messages to computers with appropriate IP addresses
Wireless Access Point
Can be connected to hub, switch, or router; many routers now also act as a wireless access point; sends out a wireless signal so computers on the network can connect without a cable
Circuit Switched Network
Requires that a full pathway, or circuit, be est. before transmission can begin and maintained during the entire transmission; like calling someone on the phone
Packet Switched Network
A message’s pathway is only est. as it is sent; the choice of pathway is based on availability and amount of message traffic
Workstations
Creates and maintains client network connections to remote servers
Virtual Machine (VM)
A software emulator program that permits a computer user to use multiple computers and multiple platforms without the expense of purchasing multiple computers; allows a user to run software for different OS platform in their computer that would not otherwise be able to run that software; this allows multiple users on a network to access the software to support collaboration.
Server
Computers that have greater hard disk storage, faster response time and are used to respond to request from other computers on the network
Client-server Network
Contains one or more servers; client is a computer that will request information from another computer; server is a computer that takes requests and responds with the requested information; the software used facilitates communication with remote servers
File Server
Sends files over the network at the request of clients.
Responds over LAN, within one location/site.
Support both application software and data files.
Web Server
Stores data files (web pages) and programs (scripts).
Responds from anywhere on the Internet.
Database Server
Responds to queries by pulling from the database.
Typically only to local clients.
Print Server
Monitors print jobs
Mail Server
Two email servers communicate with each other
FTP Server
Like web server or file server in that requests are for files and responses are the files; data delivered between client and server.
Point-to-Point Network
Link between two resources; links two routers without any host or network in between
Bus Network
Devices connected along a single cable.
Size of network is restricted.
Star Network
Each device is connected to a central devices such as a hub or switch.
Ring Network
Each device is connected directly to its neighbors, and messages are forwarded from device to device until the proper destination is reached.
Mesh Network
Every device is connected directly to every other device in the network.
Domain Name Server (DNS)
Turns a user-friendly domain name, like Google.com, into an Internet Protocol (IP) address like 70.42.251.42 that computers use to identify each other on the network.
Parts of URL (Uniform Resource Locator)
Protocol, Domain name, Resource/Filename
Domain Name
Identifies the server on which the web page can be found
Domain Name Parts
Top level domain (TLD) name and Host name
Host Name
Identifies the organization that is responsible for the information on the page or provides the server space where the information is stored
TLD(Top Level Domain) Name
Always ends with a period and a three or two letter extension which signifies the type of organization or country associated with the page
Resource/Filename ID
Indicates the name of the file you are accessing, or the location of the document on the server
CIA
Confidentiality, Integrity, Availability
Confidentiality
Requires that data bet kept secure so that they are not accidentally provided or obtained by unauthorized users
Integrity
Requires that data is correct
Availability
Requires that information is available when needed
Data Integrity Efforts
1st - Must include a component that ensures the accuracy of the collected data
2nd - Must be entered into the system accurately
3rd - Data modification must be tracked
Strategic Risk Analysis
- Identify the organization’s information assets
- Identify vulnerabilities of each asset
- Determine threats
- Prioritizing risks
- Develop and enact policies that will reduce threats
Information Security Classifications
Public - available through public sources; includes names and addresses
Sensitive - not considered a threat to a person’s privacy if others learn of it; include email addresses
Private - information that could be a threat if disclosed to others; includes social security and credit card numbers
Confidential - information that an organization will keep secret; includes patentable information and business plans
Defense in Depth
Protecting every layer that surrounds data
Phishing
Emails to people to redirect them to a website to perform some operation but the website is a fake and just takes the information
SQL Injection
An attacker issues a SQL command to a web server as part of the URL or as input to a form on a company’s website; web server might pass the command onto the database which then allows potentially anything to be done to the database
Buffer Overflow
Placing malicious code into the buffer so that it can be executed once stored in memory; oldest and most well known software exploit; software engineers can protect against this when writing code
Hacking
When an individual obtains unauthorized access to a host
White Hat Hacker
Informs companies of potential problems with software so companies can fix
Black Hat Hacker
Individuals with malicious intent who violate security in order to commit crimes or acts of terrorism
Grey Hat Hacker
Engage in both white and black hat types of hacking activities
Packet Sniffing
Allows you to obtain anything being sent over a network if the data being transmitted isn’t encrypted
Virus
Software that attaches itself to another legitimate software application
Worms
Self contained programs that do not need other programs to propagate across computers and computer networks
Trojan Horse
Type of virus that completely replaces an existing application and takes the name of the taken over file
Denial of Service (DOS)
One or more attackers attempt to flood a server with so many incoming messages that the server is unable to handle legitimate business
Firewalls
Can be either software or hardware; hardware is a dedicated server; software contains a list of the rules that describe the types of messages that should either be permitted to make it through, or those that should be blocked
Anti-virus Software
Attempts to identify if a file contains a virus or some form of malware
Redundancy
Ensures proper storage of data by providing a means so that data is available even when storage devices are damaged or offline
Encryption
Idea of obfuscating the information that resides on a computer or sent over a network so that if it is intercepted the hacker will be unable to use the information
Symmetric Key Encryption
Uses the same key for performing the encryption and decryption
Public Key Encryption
Uses two keys, a public and private key for performing encryption and decryption
Security Education
Users learn how to protect their passwords and other security measures
Authentication
Proving you are who you say you are which can be done by: what you know, what you have (two factor authentication)
Role-based Access Control
Ensures that the user gains access only to the resources that the user should be able to access
Computer Network Advantages
- Cost savings benefits
- Increased efficiency and productivity
- Increased facilitation of communication
Application Software
Consists of programs that end users run to accomplish tasks
System Software
Consists of programs that make up the OS; software that directly supports the computer system itself
Server Software
Works with hardware to provide a network service
Local Applications
Software that is stored on an individual computer
Intranet
A LAN that uses the Internet Protocol
Cloud Computing
Offers, as a service, the ability to offload computation and storage from your local computer
Operating Systems
Primary task is to allow a computer user to easily access the hardware and software of a computer system
Kernel
Core components of the OS that is loaded when the computer is first booted.
Device Drivers
Provide specific interfaces between the OS running a computer and hardware devices.
Shell
An interface for the user, often personalized for that given user, that provides access to the kernel.
Services
OS programs that are usually started when the OS is loaded and initialized, but they run in the background. Also called daemons.
Utility Programs
Programs that allow the user to monitor and improve system performance.
Proxy Server
Acts as a giant cache of web pages that anyone in the organization has recently retrieved; can be used to block access to certain web pages
Proprietary Software
Software purchased from a vendor; also known as commercial
Shareware
Provides a trial version of the software.
Freeware
Usually software that has become obsolete; is free
Public Domain
Software that has been moved into the public domain; can be used however you feel
Open Source
Created in the Open Source Community and made freely available as source code
Copyrights
Protect an original work (in its tangible, expressed form), but not the ideas behind the work for the duration of the author’s life plus 70 years; protects against duplication.
Patents
Protect the creation of inventive concepts as well as the tangible work product for 20 years from the filing date
End User License Agreement (EULA)
Gives the purchaser the right to use the software
Decimal
Uses base 10 to represent numbers (0 - 9)
Binary
Uses base 2 system (0 and 1)
Byte
8 bits; a single character of text in a computer
Octal
Every value is represented with some combination of 8 digits (0 - 7)
Hexadecimal
Uses a base 16
Character Representation
ASCII and Unicode
Language Translators
A program that takes one program, written in a high level language, and creates a machine language program as output
Compiled Language
Translates the entire program using a compiler, creating an executable program which can be run at a later time; the program can then be run as many times as one likes, without having to re-translate each time.
Interpreted Language
Takes the most recently entered instruction, translates it into machine language, and executes it; must be translated manually each time.
Script
A computer language with a series of commands within a file that is capable of being executed without being compiled.
Algorithms
A formula or procedure for solving a problem. Can also be described as a set of steps that are followed in order to complete a process
Multi-tier Development
Separation of different aspect of a system
N-tier Development
Often used to indicate that the number of tiers a system will be broken down into will vary between different software development projects
Presentation Tier
Tier where the user interface for the system is developed; shields the user from the underlying logic of the systems as well as the underlying data structures
Logic Tier
Tier that sits between the user interface and the data.
Data Tier
Tier where data is stored, retrieved and updated from database tables
Model-View-Controller (MVC)
A development technique used in the implementation of user interfaces
The Model
Can take on different forms depending on the complexity of the application; in certain instances, it is an actual object that is an actual implementation of the application
The View
The part of the application that represents the user interface; used to capture input from the user to be passed on via the controller to the model
The Controller
The part of an application that interacts with the user and passes the user requests to the model
Data Validation
Ensuring that users enter the correct data type
String Data
Alphanumeric or text character
Floating-point
Number with a decimal point
Boolean/Logical
True/False; applying AND/OR when searching for data.
Flat File Database
One large single table; used if the amount of data that is being recorded is fairly minimal
Relational Database
Has multiple tables (relations) with interrelated fields; most common structure for databases
Hierarchical Database
Organizes data using a tree like or organizational chart type structure
Database Management System (DBMS)
Used to create, manipulate, and access the data in a database
Relation
Often presented as a table; for example: name and phone number
Tuples
Rows of a relation in a database
Attributes
Columns of the relation
Field
Contains the data of an attribute for a record within a relation
Query
A search of data in the relation or relations that fit specific parameters
Projection
A query that returns all of the records from the relation, but only select attributes or fields
Sort
Sorting records based on some field(s) such as ascending order by last name
Join
Withdraws information from multiple relations and combines them.
Primary Key
A field in the relations that contains a unique value, such as a license plate, phone number, or Social Security Number.
Business Intelligence
A specific information system to help an organization reach its strategic goals
Data Warehouse
A collection of organized databases
Database Information Processing (OLAP)
Online Analytical Processing; a computer-based technique of analyzing data to look for insights
Slicing
Creates a subset of the data by reducing the data from multiple dimensions to one dimension
Dicing
Creates a subset of the data that can still be in multiple dimensions
Drilling up and down
Shifts the view of the data; down provides more detail, up provides summarized data
Rolling up
Similar to drilling up but it collapses the data from multiple items into a single value
Pivot
Rotates data to view the data from a different perspective (being able to compare different sets of facts)
Online Data Processing (OLDP)
Deals with data in real time
Event-driven Processing
Uses business event to trigger messages to be sent by middleware between software modules that are completely independent of one another
Batch Processing
Processing large amounts of data all in one batch when the computer system is not busy
ODBC (Open Database Connectivity)
An interface for accessing database management systems that can be ported to other systems by using a driver.
Database Interacting Format
SELECT fields FROM tables WHERE fields from tables match criteria
SELECT
Used to inform the DBMS what fields or attributes are of interest
FROM
Used to inform the DBMS what tables are to be interrogated by the query and if more than one table, how they are to be combined or joined
WHERE
Used to inform the DBMS of the specific criteria the data should match to be returned as the output of the query
Project phases
Initiation, planning, executing and controlling, and closing
Project Initiation
Problem definition, resource allocation, risk assessment
Project Planning
Organize activities, time estimation, cost estimation
Project Executing and Controlling Reports
Variance reports, Status reports, Resource Allocation reports
Scope Creep
Adding to the scope of the project; can impact the allocation of resources.
Unnecessary Requirements
Requirements that are not actually needed but are “nice to have”
System Development Life Cycle (SDLC)
A process for planning, creating, testing, and deploying information systems, including hardware and software
Common Steps in SDLC
Preliminary investigation, Analysis, Logical design, Physical design, Implementation, Maintenance
Preliminary investigation
Assesses the feasibility of the proposed project and selects a development methodology
Analysis
Determines the user requirements for the new system and develops logical models of the system
Logical design
Logical models are revised to ensure that the new system will meet the user requirements identified in the first step
Physical design
Logical models are converted into physical models
Implementation
Begin converting the models from the previous steps into the actual system; this step also includes installing hardware, testing the system, and training the end users
Maintenance
Modifications or corrections to the system are made
Alpha Testing
System developers assist end users as they interact with new system; simulated data is used
Beta Testing
Performed by the end user without any assistance from the system developers; live data in a real working environment is used.
User Acceptance Testing
Employed to assess whether the system does what the user expects and to ensure that it functions in a way that is useful to the user
System Deployment
- System Conversion
- Final Documentation
- End User Training
Direct Conversion
Old system is turned off and the new system is turned on at a specific data and time
Parallel Conversion
There is a period of time in which both systems are operating concurrently
Pilot Conversion
Involves starting the conversation with a portion of end users
Phased Conversion
Deploys a subset of the system first, rather than deploying the whole system at once
Business Continuity
The activity performed by an organization to ensure that critical business functions will be available to customer, suppliers, regulators, and other entities that must have access to those functions.
Image backups
Create a copy of everything that is on a hard drive
Full backup
Everything on the hard drive is copied each and every time a backup is performed
Incremental backup
An initial full backup is completed and then subsequent backups only capture the changes since the last backup
Data mirroring
The OS writes data (and changes to data) to multiple hard drives at the same time.
Off-Site Storage
A secure location for storing backup media
Hot Site
Physical location where an organization can move its operations that includes everything for normal business operations; quickest return to business but very expensive.
Cold Site
Physical location like a shell that can be used for operations should the need arise; not equipped with hardware, servers, etc.; cheaper to have
Site Sharing
Having multiple data centers located in disparate regions; typically used by large organizations.
The Internet of Things (IoT)
Refers to the myriad types of devices that can and will be connected to the Internet in the next few years.
Big Data
Refers to data sets that are so large and complex that they will require more advanced database management/processing tools.
SaaS
Software as a Service. Can access and use software through the Internet.
PaaS
Platform as a Service. Intention is to be able to quickly and reliably develop and deliver applications.
LaaS
Logging as a Service. All resources an IT dept. needs are located outside of the organization and are accessible by anyone, anywhere.
Ethics
A code of moral conduct or a set of principles that govern behavior.
Administrator Ethics
Privacy, Ownership, Control, Accuracy, Security
Transistor
A device used to amplify or switch electronic signals and electrical power.
Loops
Instructions that continually repeat until a certain condition is reached.
White Loop
Used when we do not know how many a loop needs to be executed beforehand.
For Loop
Used when we already know how many times a loop needs to be executed.
IP Aliasing
Associating more than one IP address to a network interface.
IP Address
A code that identifies each computer using the Internet Protocol to communicate over a network.
SQL
Programming language for managing data in a database management system.
Buffer
Physical memory storage used to temporarily store data while being moved from one place to another; can read faster than RAM but cannot store as much.
LAN
Local Area Network; connects computers within a limited area such as a school or business.
Database Driver
A program that implements a protocol for connecting to a database,
Dumb Terminal
A display monitor that has no processing capabilities.
ASCII
The first character encoding standard; represents English characters as numbers, with each letter assigned a number from 0 to 127.
Unicode
Defines the internal text coding system in nearly all operating systems; assigns each character a unique number.
Motherboard
The main circuit board of a computer; it holds and allows communication between many electronic system components, such as the CPU and memory, and provides connectors for other peripherals.
Non-Volatile Memory
Memory that retains contents when power is turned off, such as ROM; RAM is volatile.
Telnet
Allows a user to communicate with a remote device; does not use encryption.
SSH (Secure Shell)
Allows a user to communicate with a remote device; does use encryption.
Integer
A whole number (non-fraction) that can be positive, negative, or zero, but it cannot have decimal places.
ETL
Extract Transform, Load; process of extracting data, transforming it for purposes of analysis, and loading it into the final target database.
Variance Report
Used to identify the difference between the planned outcomes and the actual outcomes.
Waterfall Model
Used during the system development life cycle (SDLC) to denote the fact that each step should be completed one at a time.
HIPAA
The safeguard of medical information.
FERPA
Protects student education records.
SEAL
The Digital Signature and Electronic Authentication Law (SEAL) of 1998.
Brute Force
The process of using all possible combinations of letters and numbers to crack a password.
Programming languages used for automation
TCL and Python
