Diagram of Comsci G12 Midterms | 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

Internet

- Interconnected set of networks and computers

- Permits transfer of data

- Permits delivery of services

- Data transfer governed by protocols (TCP/IP)

- Protocols and guidelines developed by W3C

World Wide Web (WWW)

- Set of hypertext-linked resources

- Resources identified by URIs (unique resource identifier)

- Transfers data between client and server via internet

- Resources can be read using a browser

Web 1.0

Consisted of read-only webpages made for information sharing; one-way content

Web 2.0

Consisted of read and write webpages in which people could interact, often used for social media; two-way content

Web 3.0

Consists of webpages that can read, write, and execute, designed for immersion; interconnected content

Hypertext

Text displayed with references (hyperlinks) to other text/files that the reader can immediately access, i.e. wikipedia.org links to Wikipedia's files

HTTP

Hypertext Transfer Protocol, governs transfer or exchange of hypertext. Protocol exists on the application layer

HTTPS

Hypertext Transfer Protocol Secure. Encrypts data wiht SSL or TLS to create a more secure form of HTTP

URL

Universal Resource Locator. Defines a pathway to a resource, i.e. web addresses. Consists of a protocol, domain name, directory, and file

Markup Language

Language that uses tags to annotate the information in a document for structuring, organization, and formatting

HTML

Hypertext Markup Language. Markup language for describing structure of a web page. May retrieve content with hyperlinks, and displays content sent over the internet

XML

Extensible Markup Language. A language for storing and transporting data. Extensible = easy addition of new information. Provides a common platform for sharing document information across applications.

XSLT

Extensible Stylesheet Language Transformations. Transforms XML into an output document, and contains template rules/instructions

JavaScript (JS)

Scripting language to add functionality to webpages. It is embedded into HTML along with CSS. Code is executed when page is download or an "event" (such as button press) is triggered, and allows dynamic web pages (changeable content without reload).

CSS

Cascading Style Sheets. Describes the visual presentation of a webpage, and is independent from HTML

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.

Components of a Web Page

Header, Body, Footer, Navigation Bar, Banner, Hyperlinks, Sidebar

Meta tags

Information within the header that contains information about the webpage for search engines

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)

Search Engine

A program that searches for and identifies items in a database that correspond to keywords or characters specified by the user, used especially for finding particular sites on the World Wide Web

Web Crawler

A program used by search engines to maintain real-time information by looking at metatags

SEO

Search Engine Optimization. Helps website to be better "crawled", or searched, by search engines

News Page

A website that provides relevant articles, audio and video on current news

Business Page

A website that is used to officially represent a brand on the Internet, and which is often used as the landing page for advertising content

Personal Page

A website created by an individual, or small group like a band, to contain content of a personal nature rather than content pertaining to a company, organization or institution

Blogs

Web log. A regularly updated website typically run by an individual or small group, that is written in an informal or conversational style on a particular topic

Forum

An online discussion site where people can hold conversations in the form of posted messages

Ecommerce Pages

Online portals that facilitate online transactions of goods and services through means of the transfer of information and funds over the Internet

Wiki

A website that allows collaborative editing of its content and structure by its users

Social Media

Forms of electronic communication (such as websites for social networking and microblogging) through which users create online communities to share information, ideas, personal messages, and other content (such as videos)

Static Webpage

Fixed webpage that does not change unless re-designed on the serverside. Allows no interaction nor any input