Introduction to Information Systems Flashcards
Processor
Performs tasks and manipulates data
Memory
Storage used as working space; all data of memory is lost when the computer is off.
Volatile storage
Memory that can’t retain data without power
Secondary storage
Long-term storage (aka hard drive, also USB); non-volatile, data is retained when the computer is off
Input device
Devices that help you interact with the computer; ex. keyboard, mouse
Output device
Devices that help you see what the computer is doing; ex. monitors, printers
Traditional hard drives
Spinning disks move
Newer hard drives
Solid state disks (SSD) with non-volatile memory chips
Which are faster: SSD or spinning disks?
SSD
Binary
Using 1’s and 0’s
Byte
When 8 bits are grouped together
1 kilobyte (KB)
1024 bytes
1 megabyte (MB)
1024 KB
1 gigabyte (GB)
1024 MB
1 terabyte (TB)
1024 GB
Fault tolerant disk configuration
A single hard disk in the server failing does not cause the loss of data
Redundant power supplies
Power supply in a computer converts the AC power from the wall outlet to the DC power used internally by the server
Memory (servers)
Servers need more intensive memory for applications to run; will commonly have 128 GB or more
Multiple processors (servers)
Servers commonly have 2 processors to increase processing abilities (work for a single processor is split between 2)
Server virtualization
Divides hardware capacity of an individual server and allocates it to virtual machines
Advantages if using virtual machines
-Increases efficiency to 75% used, when 90% of the physical server was sitting idle
-Easier to move VM to new hardware
-Failure of physical server results in only a few minutes of downtown until VM run it; high availability
-Fast to deploy, can be created in minutes
Software
Set of instructions that tells a computer what to do
Applications
Accomplish tasks with a computer; provides user interface for interactivity (ex. Microsoft Office); needs certain operating services to access certain applications
Operating system
Responsible for managing and using the hardware and provides application programmer interfaces (ex. Windows 10, MacOS)
Services
Runs in the background and do not provide a user interface (ex. Microsoft SQL)
Client-server (Application)
Processing tasks are divided among multiple computers, each computer has a different task. Two parts: client allows users to interact with the application and the server is associated with data storage and processing. Ex. web browsing - the client is the web browser and server is the web server accepting requests from the web browser and responds with data to be displayed on the web browser.
Peer-to-peer (Application)
Specialized application that function without the need for a centralized server, designed to be resilient. Less common than client-server.
Web-based applications
Installed on a web server and typically uses a back-end database for data storage. User interface is a web browser.
Advantages of web-based applications
-Provides flexibility and functionality across different operating systems
-Maintenance is easy
-Servers are automatically updated and immediately available
Cloud computing
Organization’s access to computing resources or services from a third party over the internet; IT outsourcing and is purchased as a commodity.
Cloud-based applications
Web-based but can also be done with remote desktop. AKA “software as a service”
Cloud-based services to build applications
Provides building blocks to build applications. Ex. Online storage and online database
Cloud-based virtual machine
Virtual machines that are run in the data center of a cloud provider; highly available. Ex. Microsoft SQL server can include SQL VMs.
Advantages of cloud computing
-More efficient to have one large provider to manage the application
-No large capital investment (do not need to purchase hardware or software)
-Scale up or down as required
-No need to maintain or upgrade
-Access the service or data from anywhere (as long as there’s internet connection)
-Access to larger IT talent pools
-Ability to handle peaks in processing
-Focusing management’s attention in core business
-Better disaster recovery
Disadvantages of cloud computing
-Ongoing licensing fees are more expensive than purchasing it and running it locally
-Customization is limited; orgs may need to change business processes
-Less control of security, privacy, service, or data
-Difficulty to move data between cloud providers
-Risk to data if the provider goes out of business
