AP CompSci Vocab

Input

data that are sent to a computer for processing by a program. Can come in a variety of forms, such as tactile interaction, audio, visuals, or text.

Output

any data that are sent from a program to a device. Can come in a variety of forms, such as tactile interaction, audio, visuals, or text.

User Interface

The inputs and outputs that allow a user to interact with a piece of software. User interfaces can include a variety of forms such as buttons, menus, images, text, and graphics.

Documentation

A written description of how a command or piece of code works or was developed

Comment

Form of a program documentation written into the program to be read by people which do not affect how a program runs

Pair Programming

A collaborative programming style in which two programmers switch between the role of writing code and tracking or planning high level progress.

Binary Number

A base 2 number with two possible different digits

Byte

8 bits ex. 10010101

Bit

A contraction of “Binary Digit” the single unit of information in a computer, typically represented as a 0 or 1

Overflow Error

Error from attempting to represent a number that is too large. (Not enough bits)

Round-off Error

Error from attempting to represent a number that is too precise. The value is rounded.

Sampling

A process for creating a digital representation of analog data by measuring the analog data at regular intervals called samples

Analog Data

Data with values that change continuously, or smoothly over time. Ex. live music, colors of a painting, position of a sprinter during a race.

Digital Data

Data that changes discreetly through a finite set of possible values. Ex. digital image, mp3 file

Lossless Compression

A process for reducing the number of bits needed to represent something without losing any information. This process in reversible.

Lossy Compression

A process for reducing the number of bits needed to represent something in which some information is lost or thrown away. This process in not reversible.

Intellectual Property

A work or invention that is the result of creativity, such as a piece of writing or a design, to which one has rights and for which one may apply for a patent, copyright, trademark, etc.

Creative Commons

A collection of public copyright licenses that enable the free distribution of an otherwise copyrighted work, used when an author wants to give people the right to share, use, and build upon a work that they created

Computing Device

A machine that can run a program, including computers, tablets, servers, routers, and smart sensors

Computing Network

A group of interconnected computing devices capable of sending or receiving data

Computing System

A group of computing devices and programs working together for a common purpose

Path

The series of connections between computing devices on a network starting with a sender and ending with a receiver

Bandwidth

The maximum amount of data that can be sent in a fixed amount of time, usually measured in bits per second

Protocol

An agreed-upon set of rules that specify the behavior of some system

IP Address

A unique number assigned to each device on the Internet

Internet Protocol

A protocol for sending data across the internet that assigns unique numbers (IP addresses) to each connected device

Router

A type of computer that forwards data across a network

Fault Tolerant

Can continue to function even in the event of individual component failures. This is important because elements of complex systems like a computer network fail at unexpected times, often in groups

Redundancy

The inclusion of extra components so that a system can continue to work even if individual components fail, for example by having more than one path between any two connected devices in a network

Transmission Control Protocol (TCP)

A protocol for sending packets that does error-checking to ensure all packets are received and properly ordered (prioritizing accuracy)

Packet

A chunk of data sent over a network. Larger messages are divided into packets that may arrive at the destination in order, out-of-order, or not at all.

Packet Metadata

Data added to packets to help route them through the network and reassemble the original message

User Datagram Protocol (UDP)

A protocol for sending packets quickly with minimal error-checking and no resending of dropped packets (prioritizing speed)

Datastream

Information passed through the internet in packets.

Scalability

The capacity for the system to change in size and scale to meet new demands

World Wide Web

A system of linked pages, programs, and files

Hypertext Transfer Protocol (HTTP)

A protocol for computers to request and share the pages that make up the world wide web on the Internet

The Domain Name System (DNS)

The system responsible for translating domain names like example.com into IP addresses

Digital Divide

differing access to computing devices and the Internet, based on socioeconomic, geographic, or demographic characteristics.

• Can affect both individual and groups.

• Raises ethical concerns of equity, access, and influence globally and locally.

• Affected by the actions of individuals, organizations, and governments.

Expression

A combination of operators and values that evaluates to a single value

Assignment Operator

Holds one value at a time

Variable

Allows a program to change the value represented by a variable

String

a data type found in computer programming that consists of alphanumeric characters (letters and numbers).

Boolean Value

True or false

Boolean expression: evaluates to either true or false

Relational Operators

Comparison operators: <,>,<=,>=,==, !=,

Logical operators: &&, ||, !

Conditional Statement

Affects the sequential flow of control by executing different statements based on the value of a Boolean expression

Logical Operator

NOT, AND, and OR, which evaluate to a Boolean value

Function (Procedure)

A named group of programming instructions. Also referred to as a “procedure”

Function (Procedure) Call

A command that executes the code within a function

Correlation

Similarities, patterns

Metadata

Data about data

Data Filtering

Filtering data allows the user to look at a subset of the data.

Data Cleaning

When data is incomplete, invalid, or multiple tables are combined into one, users can manually clean the data

Citizen Science

Citizen science is research where some of the data collection is done by members of the public using own computing devices which leads to solving scientific problems

"collecting data from others so you can analyze it"

Crowdsourcing

Crowdsourcing is the practice of obtaining input or information from a large number of people via the Internet.

Data Bias

Data bias refers to data that is incomplete or inaccurate. These limitations then fail to paint an accurate picture of the population the data is supposed to represent. Data can represent anything like standardized test scores of college students, customer satisfaction feedback, or population health data.

Information

facts provided or learned about something or someone.

List

A List is an ordered collection of elements

Index

An index a common method for referencing the elements in a list or string using numbers

Element

An Element is an individual value in a list that is assigned a unique index

Iteration

A repetitive portion of an algorithm which repeats a specified number of times or until given condition is met

Infinite Loop

Occurs when the ending condition will never evaluate to true. In other words, the Boolean expression will never evaluate to false

Traversal

the process of accessing each item in a list one at a time with a for loop

Parameter

A variable in a function definition. Used as a placeholder for values that will be passed through the function.

Argument

Value passed to the parameter

Return

Used to return the flow of control to the point where the procedure (also known as a function) was called and to return the value of expression

Procedural Abstraction

Provides a name for a process and allows the procedure (function) to be used only knowing what it does, and not necessarily how it does it. (makes something look simpler than it really is → hides complexity)

Library

A group of functions (procedures) that may be used in creating new programs

Application Program Interface (API)

specifications for how functions in a library behave and can be used

Modularity

The subdivision of a computer program into separate subprograms

Personally Identifiable Information (PII)

Information about an individual that identifies, links, relates, or describes them

Malware

Software intended to damage a computing system or take partial control over its operation

Phishing

A technique that attempts to trick a user into providing personal information. That personal information can then be used to access sensitive online resources, such as bank accounts and emails. 

Keylogging

The use of a program to record every keystroke made by a computer user in order to gain fraudulent access to passwords and other confidential information

Rogue Access Point

A wireless access point that gives unauthorized access to secure networks

Encryption

A process of encoding messages to keep them secret, so only “authorized” parties can read it.

Decryption

A process that reverses encryption taking a secret message and reproducing the original plain text

Symmetric Key Encryption

Involves one key for both encryption and decryption

Public Key Encryption

Pairs a public key for encryption and a private key for decryption. The sender does not need the receiver’s private key to encrypt a message, but the receiver’s private key is required to decrypt the message.

Cracking Encryption

when you attempt to decode a secret message without knowing all the specifics of the cipher, you are trying to crack the encryption

Cipher

The generic term for a technique (or algorithm) that performs encryption

Caesar’s Cipher

A technique for encryption that shifts the alphabet by some number of characters

Multifactor Authentication

A method of computer access in which a user has to successfully provide evidence in at least two of the following categories: knowledge (something they know), possession (something they have) and inherence (something they are). Each step provides a new layer of security.

Computer Virus Scanning Software

Protects a computing system against infection

Problem

A general description of a task that can (or cannot) be solved with an algorithm

Algorithm

A finite set of instructions that accomplish a task

Sequencing

Putting steps in an order

Sequencing

Putting steps in an order

Selection

Doing some steps over and over

Efficiency

A measure of how many steps are needed to complete an algorithm

Linear Search

A search algorithm which checks each element of a list, in order until the desired value is found or all elements in the list have been checked

Binary Search

A search algorithm that starts at the middle of a sorted set of numbers and removes half of the data; this process repeats until the desired value is found or all element have been eliminated

Unreasonable Time

Algorithms with exponential or factorial efficiencies are examples of algorithms that run in an unreasonable amount of time.

Reasonable Time

Algorithms with a polynomial efficiency or lower (constant, linear, square, cube, etc.) are said to run in a reasonable amount of time

Undecidable Problem

A problem for which no algorithm can be constructed that is always capable of providing a correct yes-or-no answer

Heuristic

Provides a “good enough” solution to a problem when an actual solution is impractical or impossible