Comsci Paper 1 - flashcards | Quizlet

Hardware

All of the physical parts of a computer, network, etc.

Components

Internal hardware of a computer

Peripherals

External hardware used for input/output (I/O devices)

Software

A general term that describes computer programs or sets of instructions that are used on computer/network systems

Operating System (OS)

System software that manages hardware and software resources to provide common services for a device

Desktop Programs

Software that is installed and runs from the OS of a device

Web Applications

Software that runs on a web server and must be accessed via a web browser. Many also have apps as well

Mobile App

Software that is run on a mobile device

Network

A set of computer systems that are interconnected and share resources as well as data

WAN

Wide Area Network. Regional/Country level network; multiple LANs make up a WAN

LAN

Local Area Network. Office/Business/Home level network

Human Resources

All of the people within an organization that use the technology. Includes end-users (uses hardware/software) and technology managers (sets up hardware/software)

Client

Hardware/software that accesses a service made available by a server, and sends requests for data/service

Server

Program/host computer that fulfills requests (provides data) from clients (may reside in the same or other computers)

Router

Routes data at the network level (chooses where data goes)

Firewall

A barrier/filter between a trusted system and the outside world, designed for security

Switch

Connects devices to form a network (servers and/or clients)

CPU

Central Processing Unit. The key component of a computer system, which contains the circuitry necessary to fetch, decode and execute program instructions from and to main or random access memory (RAM)

Busses

Electrical connections that connect the CPU to other components in order to transport data. Normally built into the motherboard

TERM

Address Bus

DEFINITION

Links RAM to CPU via MAR

TERM

Data Bus

DEFINITION

Links RAM to CPU via MDR

TERM

Control Bus

DEFINITION

links RAM to CPU via CU

TERM

RAM

DEFINITION

Random Access Memory. Stores and processes the data and instructions the computer has loaded since starting up and everything the user has opened/loaded. Counts as volatile and primary memory

How data is transferred between CPU and storage

Program data is fetched from storage and placed in the RAM. Each instruction is then executed by the CPU one at a time

TERM

MAR

DEFINITION

Memory Address Register. Fetches the next RAM address of the instruction the CPU wants, through the address bus

TERM

MDR

DEFINITION

Memory Data Register. Fetches data from the specific RAM address given by the MAR, through the data bus

TERM

CU

DEFINITION

Control Unit. Stores fetched addresses, and controls the flow of data in the CPU. Decodes data from MDR into an instruction, which is then held in the IR (Instruction Register) and passed to the ALU

TERM

ALU

DEFINITION

Arithmetic Logic Unit. Executes all arithmetic (+/-) and logic (and/or) instructions that come from the CU. May be referred to as cores, which all process simultaneously

TERM

Cache

DEFINITION

Small, high-speed memory both inside and close to the CPU, used to hold frequently used data. Allows CPU to access RAM (slower) less frequently. Counts as volatile and primary memory

Volatile Memory

Memory that loses its contents when the power is turned off

Non-volatile Memory

Memory that retains its contents when the power is turned off

Primary Storage

Volatile memory with high read/write speed, such as RAM, ROM, and Cache

Secondary Storage

Non-volatile memory with slower read/write speed, such as HDDs and SSDs

Tertiary Storage

Internet/Cloud storage

Offline Storage

Non-volatile memory that is fully offline, such as CD-RW, DVD-RW, Blue-ray, USB, and Tape Drives

ROM

Read Only Memory. Non-volatile, permanent memory that is read only and can not be changed

BIOS

Basic Input/Output System. A small ROM program that allows the computer to know how to find the operating system to 'boot' the computer after power is restored

Speed/Cost/Size of Memory

As memory read/write speed increases, the cost also increases, but the size decreases

Machine Cycle

Also called the fetch-execute cycle. Fetch=>Decode=>Execute=>Store

Program Counter (PC)

The register that keeps track of instructions: it contains the address of the next instruction to be executed

Persistent Storage

Non-volatile storage to store long-term data, similar to secondary storage

Fundamental Operations of a Computer

Add, Compare, Retrieve, and Store

Add

Takes a value and adds it to the ALU (which already has a current value stored)

Compare

Compares to results or values

Retrieve

Retrieves data/instructions from the RAM

Store

Takes a result and stores it in the RAM

Machine Code

A computer programming language consisting of binary or hexadecimal instructions which a computer can respond to directly

Assembly Code

A low-level symbolic code (often the fundamental instructions, e.g. ADD, STORE) converted by an assembler

Compound Operation

An operation which consists of multiple fundamental operations, often both reading and writing, executing simultaneously, e.g. +=, *=

Natural Language

Languages that happen in nature, e.g. animal/human language, english. Key characteristics: varying vocabulary, ambiguous, grammar/syntax may be inconsistent

Computer Language

Languages that computer speak, ranked from low to high level. Key characteristics: fixed vocabulary meaning only one thing (i.e. print, string), unambigous meanings (i.e. marcell='short'), grammar/syntax consistency (i.e. print(f'') stays as print(f''))

Readability/Speed/Language Level

As the computer language level increases, so does the readability, but execution speed decreases

High Level Language

Computer language containing more natural language, but requires more interpretation from the computer (decreases execution speed)

Low Level Language

Computer language closer to binary code used by machines, which requires less interpretation (higher execution speed) but harder to read by humans

Interpreter/Translator

Converts high level language to machine language as program is running.

Key characteristics: translates one line at a time, needed every time program is run, returns list of errors, runs slowly as code needs to be translated every time.

Compiler

Converts high level language to machine language as a single file/executable program.

Key characteristics: translates all code simultaneously, needed only once to create executable, only returns first error, compiling may take a long time but compiled file runs quickly.

Assembler

Converts assembly language to machine language.

Key characteristics: uses instruction set given by processor to convert, runs quickly as its simply direct translation

Virtual Machine (VM)

Software that emulates a simulated environment of another, and allows use of multiple systems on one computer

Variable

Storage location for data in a program. Can be changed during the program, and should not clash with reserved words (i.e. print, string). May hold many data types (i.e. integer, string)

Constant

A variable that can not change, fixed value (i.e. PI=3.14, GRAVITY=9.81)

Operators

Set of characters that represents an action.

4 types: boolean (true/false), arithmetic (basic math), assignment (=, +=, etc.), comparison (<, >, etc.)

Object

An instance of a class. It is a collection of data and methods, created from a "template" (class)

Conditional Statement

Describes relationship between two events based on certain conditions

Conditional Logic

Sets rules/conditions that cause processes to change based on inputs

DNS

Domain Name System. Part of the TCP/IP protocol, and translates text-based web addresses to numerical IP addresses, and vice versa.

TCP

Transmission Control Protocol. Receives packets of data from an application and divides it into segments, ready for IP. Establishes an initial connection.

IP

Internet Protocol. Delivers packets of data to the correct addresses. Defines the format of a packet, and includes routing information as a header in front of the TCP to tell where the packets should go.

TCP/IP

The set of protocols that governs the transfer of data over the Internet; TCP controls the retrieval, while IP controls the delivery.

FTP

File Transfer Protocol. Protocol for transferring files over a TCP based network.

Protocol

A set of rules to successfully carry out some process, i.e. TCP/IP for data transfer

Standards

Set of technical specifications that should be adhered to, to allow for functionality/safety/quality. Allows for interoperability (ability to exchange data) and accessibility (usable by as many people possible)

Algorithm

A process or set of rules to be followed in calculations or other problem-solving operations, especially by a computer

Stakeholder

Individuals, teams, groups or organizations that have an interest in the realization of a project that might be impacted by the outcome of the project

End User

The person software/hardware is developed for

Internal Stakeholders

Stakeholders that work within the business, such as employees, managers, and owners

External Stakeholders

Stakeholders from outside the business but are interested in the business, such as suppliers and investors

Organizational Stakeholder Structures - Internal

An Internal/Infrastructure Focused Team would be a stakeholder structure which consists of employees focusing on the product or business itself

Organizational Stakeholder Structures - External

An External/Customer Focused Team would be a stakeholder structure which consists of employees interacting with customers, whether it be for research and data or for customer support

Stakeholder Engagement

A process in which a business gathers feedback from stakeholders in order to improve. This may be done through observations (direct/indirect), surveys (closed/open), interviews (structured/unstructured), or even direct collaboration.

Methods of Gathering Information

NOTE: BROADER/MORE GENERAL THAN STAKEHOLDER ENGAGEMENT

Gathering information from stakeholders may be done through examining current systems, examining competing products, organizational capabilities, or literature searches

Examining Current Systems

A method of gathering information (not necessarily stakeholder engagement) that analyzes functions and procedures, and studies both the system documentation and business documents surrounding the system

Examining Competing Products

A method of gathering information (not necessarily stakeholder engagement) that analyzes the benefits, vulnerabilities, successes, failures, breakthroughs, design features, and user/stakeholder response of a certain product in comparison to similar products in the market

Organizational Capabilities

A method of gathering information (not necessarily stakeholder engagement) that involves understanding what, as an organization, is able to be developed. This may involve looking at employee skills or quantity of employees

Literature Searches

A method of gathering information (not necessarily stakeholder engagement) that involves reviewing relevant written sources on or relating to a certain product, e.g. articles

Representing Requirements

Requirements of systems or products may need different methods of clarification depending on what's needed. These methods include: Software Requirements Specification (SRS) Document, System Flowcharts, Data Flow Diagrams, Use Case Diagrams, and Structure Charts.

NOTE: Only important thing here is system flowcharts and SRS

SRS Document

Software Requirements Specification Document. It is a description of a software system to be developed, and includes both functional requirements (specific behavior/functions, things it must DO) and non-functional requirements (more about customer experience, i.e. needs to be fast/reliable)

Shape for start/end in a flowchart

Oval

Shape for process in a flowchart

Rectangle

Shape for input/output in a flowchart

Parallelogram

Shape for decision in a flowchart

Diamond

Shapes for different storages in a flowchart

Refer to image

Data flow in a flowchart

Arrows between each shape show the flow of data

Prototype

An initial preliminary version of the final product/system which shows how the final product/system will work

Prototype Benefits

Prototypes gives an idea of the final product, customers/users can get a feel on how things work, informs employees on potential problems, and encourages active participation between users and developers. It also provides enough of the concept for a decision for production to be made

Iteration

A continually repeated process/procedure applied to a result (a product/system) of a previous application of the iteration, done to continually achieve better solutions to a problem. It helps to remove inconsistences/errors, and for better evaluation

Value of End-User Input

End-User Input is highly valuable as it is essential for an optimal success. Without it, frustration, misunderstandings, or slower adoption may occur

Creative Destruction

A process in which new innovations replace and make obsolete older innovations, e.g. Netflix replacing cable TV. May lead to changes in work patterns, increase leisure, increase reliance on technology, and increase or decrease employment opportunities

New System Implementation

New systems may be implemented for various reasons, such as: efficiency, productivity/output, and lower costs. However, they all require training for relevant stakeholders, and a feasibility study studies how well this implementation would work

Types of New Systems

There are 4 types of new systems [implementations]: completely new system, manual system to computer system, computer system replacing another, and multiple systems being combined

Completely New System

Introducing and implementing a completely new system, such as a new finance application