AP Exam Review Vocab

AP Computer Science Principles

Binary

A way of representing information using only 2 options.

Creative Commons

A collection of public copyright licenses that enable the free distribution of an otherwise copyrighted work.

Analog Data

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

Byte

Eight Bits

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 is not reversable.

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.

Overflow Error

Error from attempting to represent a number that is too large.

Sampling

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

Bit

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

Digital Data

Data that changes discretely through a finite set of possible values.

Lossless Compression

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

Round-off Error

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

Bandwidth

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

Computer System

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

IP Address

The unique number assigned to each device on the Internet.

Path

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

Computing Device

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

Protocol

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

Computer Network

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

Router

A type of computer that forwards data across a network.

Internet

A computer network consisting of interconnected networks that use standardized, open (nonproprietary) communication protocols.

Digital Divide

Differing Access to computing devices and the Internet, based on socioeconomic, geographic or demographic characteristics.

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.

HTTP

HyperText Transfer Protocol – the protocol used for transmitting webpages over the internet.

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.

World Wide Web

A system of linked pages, programs and files.

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.

Event Driven Programming

Some program statements run when triggered by an event, like a mouse click or a key press.

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.

Debugging

Finding and fixing problems in an algorithm or program

Program Statement

A command or instruction. Sometimes referred to as a code statement.

Event

Associated with an action and supplies input data to a program. Can be generated when a key is pressed, a mouse is clicked, a program is started or by any other defined action that affects the flow of execution.

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.

Documentation

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

Pair Programming

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

Program

A collection of program statements. Programs run or execute one command at a time.

Comments

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

Development Process

The steps or phases used to create a piece of software. Typically phases include investigating, designing, prototyping, and testing.

Output

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

Sequential Programming

Program statements run in order, from top to bottom.

Function

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

Variable

A named reference to a value that can be used repeatedly throughout a program.

Expression

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

Assignment Operator

Allows a program to change the value represented by a variable

Boolean Value

A data type that is either true or false.

String

An ordered sequence of characters.

Comparison Operator

Function Call

A command that executes the code within a function

Logical Operator

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

Index

A common method for referencing the elements in a list or string using numbers.

Infinite Loop

Occurs when the ending condition will never evaluate to true.

List

An ordered collection of elements

Iteration

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

Element

An individual value in a list that is assigned a unique index.

Traversal

The process of accessing each item in a list one at a time.

Data Abstraction

Manage complexity in programs by giving a collection of data a name without referencing the specific details of the representation.

Efficiency

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

Sequencing

Putting steps in an order.

Problem

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

Sequential Computer

A model in which programs run in order, one command at a time.

Selection

Deciding which steps to do next.

Heuristic

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

Reasonable Time

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

Distributed Computing

A model in which programs are run on multiple devices. Distributed Computing

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.

Algorithm

A finite set of instructions that accomplish a task

Speedup

The time used to complete a task sequentially divided by the time to complete the task in parallel.

Decision Problem

A problem with a yes/no answer (e.g. is there a path from A to B?)

Iteration

Doing some steps over and over

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 elements have been eliminated.

Optimization Problem

A problem with the goal of finding the “best” solution among many (e.g. What is the shortest path from A to B?)

Parallel Computing

A model in which programs are broken into small pieces, some of which are run simultaneously

Unreasonable Time

Algorithms with exponential or factorial efficiencies are examples of algorithms that run in

Undecidable Problem

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

Argument

The value passed to the parameter

Library

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

API

Application Program Interface – specifications for how functions in a library behave and can be used.

Procedural Abstraction

A process and allows a procedure to be used only knowing what it does, not how it does it. This allows a solution to a large problem to be based on the solution of smaller subproblems. This is accomplished by creating procedures to solve each of the subproblems.

Parameter

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

Return

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

Data Bias

Data that does not accurately reflect the full population or phenomenon being studied.

Crowd Sourcing

The practice of obtaining input or information from a large number of people via the internet.

Cleaning Data

A process that makes the data uniform without changing its meaning (e.g. replacing all equivalent abbreviations, spellings, and capitalization with the same word).

Data Filtering

Choosing a smaller subset of a data set to use for analysis, for example by eliminating / keeping only certain rows in a table.

Information

The collection of facts and patterns extracted from data.

Citizen Science

Scientific research conducted in whole or part by distributed individuals, many of whom may not be scientists, who contribute relevant data to research using their own computing devices.

Correlation

A relationship between two pieces of data, typically referring to the amount that one varies in relation to the other.

Symmetric Key Encryption

Involves one key for both encryption and decryption

Personal Identifiable Information (PII)

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

Encryption

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

Malware

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

Rouge Access Point

A wireless access point that gives unauthorized access to secure networks.

Computing Innovation

Includes a program as an integral part of its function. Can be physical (e.g. self-driving car), non-physical computing software (e.g. picture editing software), or non-physical computing concepts (e.g., e-commerce).

Public Key Encryption

Pairs 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.

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.

Decryption

A process that reverse encryption, taking a secret message and reproducing the original plain text.

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.

Multi-factor Authentication

A system that requires at least two steps to unlock protected information; each step adds a new layer of security that must be broken to gain unauthorized access.