Important Vocabulary

A

Abstraction – reducing information and detail to facilitate focus on relevant concepts

Additive Color – a color model where no light is black and the combination of all light is white, like RGB

AND – basic logic gate where every part of a statement must be true for the entire statement to be true

Application – almost everything on the computer except saved files and the operating system, including word processors, photo editing software, web browsers, games, and music programs

ARPANET – the Advanced Research Projects Agency Network, first agency to use TCP/IP

ASCII – American Standard Code for Information Interchange

Asymmetric Key Encryption – a different key is used to encrypt and decrypt a message

Atomic transaction – transaction where all components must be carried out before the transaction is considered complete such that all occur or none occur

B

Backdoor – a secret way to bypass traditional access to a device or network

Bandwidth – the amount of resources available to transmit the data

Big Data – sets of data that are larger than a consumer software application can handle

Binary – base 2, number system that uses 0, 1

Binary Search – a searching algorithm, used on sorted lists, that divides the number of elements to search in half until it is down to one element

Binary Tree – a data structure that can, at the most, have two nodes or “branches”

BIOS – Basic input/output system

Bit – each number in the binary system, 0 or 1

Bit Depth –refers to the amplitude of the analog wave and specifically to the number of bits used for each sample

Bit Rate – the number of bits that can be processed per second

Boolean Logic – a branch of algebra where variables can only have two values: true or false

Botnet – a large network of internet-robots called bots controlled by a command-and-control server, often used for DDoS attacks

Byte – 8 bits

C

Caesar Cipher – a shift cipher where each letter is shifted the same amount

Central Processing Unit (CPU) –carries out every command or process on the computer and can be thought of as the brain of the computer

Cipher – is a pair of algorithms that give details on how to encrypt and decrypt the data

Client –any computer that requests a service

Cloud Computing – using a remote server to store files

CMYK – color model used for printing. Stands for cyan, magenta, yellow, and black (key), where the number associated with each letter is the percentage of each color used

Codec– a computer program that encodes or decodes

Computationally hard – a problem that takes too long even for a computer to find the exact solution

Computer – an electronic device that processes data according to a set of instructions or commands, known as a program

Consistency – in databases, refers to the fact that information from one table does not contradict itself in any other table throughout a database

Constant – used in coding to store a value that cannot be changed

Copyright – a form of intellectual property, which protects original forms of expression

Core – the central processing unit (CPU), the main memory, the motherboard, and the power supply

CSS – Cascading Style Sheets, redefines mark-up in HTML

D

Datagrams – Similar to packets, used in unreliable protocols such as UDP

DDoS – distributed denial-of-service attack, hackers flood a site with fake request making all the site’s recourses unavailable for legitimate users

Deadlock – when, in a database, two transactions are trying to lock the same row and neither can continue until the other is complete

Debugging – finding errors in code

Decimal – base 10, number system that used 0-9

Decryption – the reverse process of encryption

Design – Implement – Test – thethree steps of the iterative development process

Dictionary– a key in metadataexplaining the instructions to encode or decode compressed data

Digit – each number in the decimal system, 0-9

Digital Certificate – a trusted third-party file that verifies a site as legitimate

Digital Divide – the gap between those who have access to technology and those who do not

Digital signature – an electronic signature that, by using public key, can be verified authentic

Discarding Data – a type of lossy compression that removes unneeded data with no way to get that data back

DNS – Domain Name System, one of the smaller networks that make up the Internet. It contains many servers that act like phone books

Domain Name – a name given or linked to an IP address

E

Encryption – taking text and converting it so it is illegible

Ethical computing – demands that users and developers hold themselves to a higher standard. Refers to the principles, values, standards, and practices that guide individuals and groups in doing what is right

EULA – end-user license agreement

F

Fault-tolerance – the ability for a system to continue to run properly even if one piece fails

Fault-Tolerant – a property of IP. If there is an error, it still works properly

Fixed-length Code – blocks of code that are always the same size

FTP – File Transfer Protocol, used for transferring files between a client and a server

G

Graphical User Interface (GUI) – an interface that uses images to represent a system’s folders and files

H

Hacker – anyone who uses their technological skills to solve problems. A malicious security hacker exploits weaknesses on a computer or network and can steal or disrupt data

Hardware – the physical parts of the computer, including devices such as the monitor, keyboard, speakers, wires, chips, cables, plugs, disks, printers, and mice

Hashing – the process of running data through a one-way function that takes data of varying sizes and returns a unique fixed length value

Heuristic approach – an approach that gives results that are “good enough” when an exact answer is not necessary

Hexadecimal – base 16, number system that uses 0-9 and a-f

HTML – Hyper Text Markup Language, the standard for creating web pages

HTTP – Hyper Text Transfer Protocol, used for websites

HTTPS – a secure version of HTTP that uses SSL/TLS

Huffman Tree – a prefix free binary tree that is the most efficient way to compress individual characters

I

Idempotency – when an operation results in the same end result no matter how many times it is performed

IMAP – Internet Message Access Protocol, used for e-mail

Incremental – done in small chunks

Input and output (I/O) devices – how the user interacts with the computer

Interframe Compression – a video compression that re-uses redundant pixels from one frame to the next, also known as temporal compression

Internet – a network of smaller networks connected using a specific set of rules that computers use to communicate with each other

Internet Protocol Suite –Often referred to as TCP/IP, the four abstract layers in the DoD Model of the Internet

Intraframe Compression – a technique used by compressing each frame of a video, also known as spatial compression

IP –Internet protocol, a unique address for every device connected to the Internet

IP Address – a unique identifier for every device on the Internet

IPv4 – the version of IP that uses 32-bit addresses

IPv6 – the version of IP that uses 128-bit addresses

ISP – Internet Service Provider

Iterative – continuously repeating steps, achieved in programming by using loops

K

Key – in cryptography, a shared secret to make encryption harder to crack

Keys – a database column that holds a unique value that distinguishes each record from others

L

Latency – the amount of delay when sending digital data over the Internet or the round-trip time information takes to get from the client to the server and back

Linear Search – a searching algorithm that starts at the first index and checks each element of the list one by one until it finds the item it is searching for

Logic bomb – code that has been placed into software that waits to run until specific conditions are met

Lossless – data compression that does not lose data during compression

Lossy – data compression that loses data during compression

M

MAC (media access control) Address – a unique, physical address that is stored in the computer’s ROM

Main memory – memory that temporarily stores information while it is being sent to the CPU, also called RAM

Malware – malicious software intended to cause damage to a computer or network

Metadata –additional data about the main data, usually at the beginning of a file

Modem – a device that handles both the modulation and the demodulation of signals

Modular arithmetic – using the remainder when dividing, also known as clock arithmetic

Motherboard (logic board) – the standardized printed circuit board that connects the CPU, main memory, and peripherals

Multi-factor authentication (MFA) – using two or more methods for verifying a user

N

Name Server – a server that contains many IP addresses and their matching domain names

Network – a group of computers that are connected so they can share resources using a data link

Nonvolatile – does not need a power supply. Information is physically written to the device

NP problem – nondeterministic polynomial time, a problem that can be verified, but not solved, in polynomial time

Nybble (or Nibble) – half of a byte, 4 bits

O

One-way Function – a problem that is easy in one direction and difficult in the other

Operating System – software that serves as an intermediate between the hardware and the applications and is in charge of keeping the entire system running smoothly

OR – basic logic gate where any part of a statement can be true for the entire statement to be true

P

P problem – polynomial time, a problem that can both be solved and verified in polynomial time

Packets – small chunks of data used in TCP/IP

Patents – allow inventors to exclude others from using their inventions without permission, can last up to twenty years

Peripherals – the input and output (I/O) devices and the secondary memory

Phishing – using “bait” to trick the user into entering sensitive information like usernames, passwords, or credit card numbers

Pixel – short for picture element. The basic unit of color on a computer display

Pixelation – when individual pixels are too large and the image begins to look blocky

POP – Post Office Protocol, used for e-mail

POST – Power-on self-test

Power Supply – converts AC electricity to the lower voltage DC electricity that is needed to power the computer

Prefix-Free Code – a specific type of variable-length code that does not use pauses

Privacy – deals with your personal information, how it is stored, and how it is shared

Private Key – a shared secret needed to decrypt a message

Protocol – a specific set of rules

Psychoacoustics – a sub-branch of psychophysics that deals specifically with sound

Psychophysics – a branch of psychology that focuses on the fact that the human eye or ear cannot perceive the loss of certain data

Public Key – a system that allows a key to be publicly published

R

Random Access Memory (RAM) –memory that can be retrieved or written to anywhere without having to go through all the previous memory

Raster – an image format that represent data in a grid of dots or pixels

Recursion – a function that references itself and consists of two parts: a recursive call and a base call

Redundancy – finding frequencies or patterns in code

Relational database – a database that has multiple tables that are connected by the use of unique keys

Reliable – a protocol that lets the client know if the server received all sent packets

RGB – color model used for most monitors or screens. Stands for red, green, and blue, referring to the color of light

Rollback – returning back to the state of a database before the write-ahead log began

Root Name Server – one of thirteen servers that contain every IP address and its matching domain name

Router – a networking device that routes Internet traffic to the destination

Run-Length Encoding – looking for redundancy or patterns as runs in the code

S

Salting – adding a random set of characters to a password before it is hashed to protect against rainbow table attacks

Sample Rate – how often an analog signal is used when converting to digital, usually measured in kHz

Secondary Memory – used for long term storage and is physically changed when files are saved or deleted

Second-Level Domain – the second highest level in the DNS hierarchy, found directly to the left of the top-level domain in a domain name

Security – refers to the steps companies take to protect your data

Selection – the logic structure in programming that uses if statements to select certain values

Sequence – the structure that runs one line after anotherin order

Sequential Memory – memory used to store back-up data on a tape

Server – any computer that provides a service

SMTP – Simple Mail Transfer Protocol

Software – includes the operating system and the applications. It is usually stored on a computer’s hard drive and cannot physically be touched. At the lowest level, it is a series of ones and zeros

Spear phishing – a type of phishing attack that targets a specific person or group using pre-existing knowledge

SSL – Secure Sockets Layer, issues digital certificates for websites

Subdomain – precedes the domain name, owned by the domain https://subdomain.domain.com

Substitution Cipher – a cipher where a letter is mapped or swapped with another letter in the alphabet

Subtractive Color – a color model where no light is white and the combination of all light is black, like CMYK.

Symmetric Key Encryption – the same key is used to encrypt and decrypt a message

T

TCP – Transmission Control Protocol, a set of rules for breaking down requests into smaller, more manageable, numbered packets

Text-Based Interface – an interface made up of purely text input from the user

TLS – Transport Layer Security, issues digital certificates for websites

Top-Level Domain – the highest level in the DNS hierarchy, found to the right of the final period in a domain name

Trademarks – protect brand names and logos in order to distinguish one company’s product from other products on the market

Traveling Salesman Problem (TSP) – an NP-hard problem that, when given distances between pairs of cities, seeks to map out the shortest route between many cities and return back to the original city

Trojan Horse – malware disguised to hide its true intent

Truth Table – a table made up of rows and columns of Boolean variables and resulting Boolean expressions

Two-factor Authentication (2FA) – a subset of MFA where exactly two methods for verifying a user are implemented

Two-phase Commit Protocol – a standardized way for databases to make sure all transactions are able to write without any inconsistencies before committing

U

UDP – User Datagram Protocol, like TCP and usually used for streaming audio/video

Uncompressed– all the information from an original file in the same format

URL – Uniform Resource Locator, specifies where to find a file on a domain

V

Variable – used in coding to store a value that can change

Variable-length Code – each data block can be a different length

Vector – an image format that represents data through a combination of points connected by lines and curves

Virtual tables – temporary tables that are made up of parts of other tables that help in reducing redundant data

Virus – a program that infects other programs and usually spreads to other programs or computers by copying itself repeatedly

VoIP – Voice over Internet Protocol, used for telephony

Volatile – needs a power supply. Turning off the power deletes information

VPN – virtual private network

W

Web (World Wide Web) – the part of the Internet that uses HTTP and HTTPS

Worm –a standalone piece of malware that can disrupt a network by copying itself repeatedly without human interaction

Write-ahead Logging – a method for avoiding inconsistencies in which all transactions are written and saved to a log before they are applied to a database