Computer science terms Flashcards
Legacy system
A system that is outdated and no longer updated
Bits vs Bytes
One byte is equal to eight bits
A bit can either be a 0 or 1
Design cycle
1.empathize
2.define
3.ideate
4.prototype
5.test
Accessibility
the practice of making your websites usable by as many people as possible (disabilities usually)
Usability
a quality attribute that assesses how easy user interfaces are to use
Implementation approaches
Pilot
Direct
Parallel
Phased
Data migration challenges
Incompatible file formats
Data structure differences
Validation rules
Incomplete data transfers
International convention on dates, currencies & character sets
Black box vs White box testing
Black box testing is when you don’t know anything about design. White box testing is when you know about the internal design and analyze it while testing
User documentation
Manuals
Change management
a systematic approach to dealing with the transition or transformation of an organization’s goals, processes or technologies
Causes of data loss
Human error
Hackers
Natural disasters
Failover system
the ability to switch automatically and seamlessly to a reliable backup system
Data loss prevention plans
Failover system
Redundancy: having data in two locations, redundant because you have it twice
Removable media: CDs, USB, tapes, etc
Offsite/online storage: External location
User acceptance testing
a phase of software development in which the software is tested in the “real world” by the intended audience
Software deployment
Computer storage options
Primary memory is the computer’s main memory and stores data temporarily. Secondary memory is external memory and saves data permanently. Data stored in primary memory can be directly accessed by the CPU, which cannot be accessed in secondary memory.
RAM
Random Access Memory
type of memory that can be accessed randomly (any byte of memory can be accessed without touching the preceding bytes).
Found in servers, PCs and other devices.
Volatile : all data is lost when device is turned off.
CPU & functions of the arithmetic logic unit
The ALU performs simple addition, subtraction, multiplication, division, and logic operations, such as OR and AND. The memory stores the program’s instructions and data.
The CPU and its elements
The control unit (CU) responsible for the operation of the CPU. It controls the retrieval of instructions from the primary memory as well as the sequence of their execution. It does the fetching of data and instructions in the fetch-decode-execute cycle.
The arithmetic logic unit (ALU)
performs all the basic arithmetic, logical or input/output operations. The CU is responsible for providing the ALU with the data that needs to be processed as well as the instructions of how the data should be processed.
The primary memory used as storage contains two types of memory - the random access memory (RAM) and the read-only memory (ROM).
The basic registers in the CPU are the memory address register (MAR) and the memory data register (MDR).
The memory address register (MAR) holds the address of the data (address - the specific location in the RAM) to be used by the ALU, so that the ALU can fetch the corresponding content from the memory and process it accordingly.
The memory data register (MDR) holds the data that is to be used by the ALU and then saved to the RAM. The MAR tells us the location and the MDR finds/fetches the data. That data/connection is done using the Data Bus.
SAN vs NAS
NAS is a single storage device that serves files over Ethernet and is relatively inexpensive and easy to set up.
SAN is a tightly coupled network of multiple devices that is more expensive and complex to set up and manage
CPU Cache memory
Cache is the temporary memory, it is a chip based feature of your computer that lets you access some information more quickly than if you access it from your computer’s main hard drive.
Identify the relevant stakeholders when planning a new system
Stakeholder: a person, group or organization that has interest or concern in an organization.
Internal stakeholders: Employees, Manager, Owners
External stakeholders: Suppliers, Society, Government, Creditors, shareholders, customers
Describe methods of obtaining requirements from stakeholders
Surveys
Interviews
Direct observation
Collecting documents
Fiber optics
Fiber optics, or optical fiber, refers to the technology that transmits information as light pulses along a glass or plastic fiber. Fiber optics transmit data in the form of light particles – or photons – that pulse through a fiber optic cable. The glass fiber core and the cladding each have a different refractive index that bends incoming light at a certain angle.
