AP Computer Science Principles Exam Review

A comprehensive set of vocabulary flashcards covering the five Big Ideas and exam logistics for the AP Computer Science Principles Exam Review (Spring 2026).

Computing Innovation

Includes a program as an integral part of its function; can be physical (self-driving car), non-physical software (picture editing software), or a non-physical concept (e-commerce).

Collaboration

The process of incorporating multiple perspectives to improve computing innovations and avoid bias during development.

Program

A collection of program statements that performs a specific task when run by a computer; often referred to as software.

Code Segment

A collection of program statements that is part of a program.

Program Behavior

How a program functions during execution, often described by how a user interacts with it.

Program Inputs

Data sent to a computer for processing by a program, which can be tactile, audio, visual, or text.

Event

An action associated with supplying input data to a program, such as a key press, mouse click, or program start.

Event-Driven Programming

A paradigm where program statements are executed when triggered by specific actions rather than through a sequential flow of control.

Iterative Development Process

A process that requires refinement and revision based on feedback, testing, or reflection, often requiring developers to revisit earlier phases.

Incremental Development Process

A process that breaks a problem into smaller pieces and ensures each piece works before adding it to the whole.

Program Specification

A definition of the requirements for a program.

Program Documentation

A written description of the function of a code segment, event, procedure, or program and how it was developed.

Comments

A form of program documentation written into the program for people to read that does not affect how the program runs.

Logic Error

A mistake in the algorithm or program that causes it to behave incorrectly or unexpectedly.

Syntax Error

A mistake in the program where the rules of the programming language are not followed.

Run-time Error

A mistake in the program that occurs during the execution of a program.

Overflow Error

An error that occurs when a computer attempts to handle a number that is outside of its defined range of values.

Bit

Shorthand for binary digit, represented as either $0$ or $1$.

Byte

A group of $8$ bits.

Abstraction

The process of reducing complexity by focusing on the main idea and hiding irrelevant details.

Analog Data

Data that has values changing smoothly over time, such as pitch, volume, colors of a painting, or the position of a sprinter.

Sampling Technique

A method used to approximate analog data digitally by measuring values of the analog signal at regular intervals.

Lossless Data Compression

Algorithms that reduce the number of bits while guaranteeing complete reconstruction of the original data.

Lossy Data Compression

Algorithms that significantly reduce bits by reconstructing only an approximation of the original data; used when minimizing size or transmission time is a priority.

Metadata

Data about data, such as file size or date of creation for an image; changes to this do not change the primary data.

Cleaning Data

A process that makes data uniform without changing its meaning, such as replacing equivalent abbreviations or spellings with a single word.

Variable

An abstraction inside a program that can hold one value at a time, which can be a single value or a collection like a list.

List

An ordered sequence of elements where each individual value is assigned a unique index.

Algorithm

A finite set of instructions that accomplish a specific task, constructed using sequencing, selection, and iteration.

Sequencing

The application of each step of an algorithm in the exact order in which the code statements are given.

Selection

Determines which parts of an algorithm are executed based on a condition being true or false.

Iteration

A repeating portion of an algorithm that continues for a specified number of times or until a condition is met.

MOD Operator

An arithmetic operator (represented as $a \text{ MOD } b$) that evaluates to the remainder when $a$ is divided by $b$.

Boolean Value

A data type that is either true or false.

Linear Search (Sequential Search)

An algorithm that checks each element of a list in order until the desired value is found or the list ends.

Binary Search

An efficient algorithm for sorted data that starts at the middle and eliminates half of the data in each step.

Procedure

A named group of programming instructions that may have parameters and return values; also called a method or function.

Parameters

Input variables of a procedure that allow it to be generalized for a range of input values.

Arguments

The specific values passed to the parameters when a procedure is called.

Procedural Abstraction

An abstraction that provides a name for a process, allowing it to be used by knowing only what it does, not how it does it.

Modularity

The subdivision of a computer program into separate subprograms.

Simulation

An abstraction of complex objects or phenomena used to mimic real-world events and draw inferences without real-world constraints.

Heuristic

An approach to a problem that produces a solution not guaranteed to be optimal, used when optimal techniques are impractical.

Decidable Problem

A decision problem for which an algorithm can be written to produce a correct output for all inputs.

Undecidable Problem

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

Computing System

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

Computer Network

A type of computing system consisting of interconnected computing devices capable of sending or receiving data.

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 a system.

Scalability

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

Packet

A chunk of data encapsulated with metadata used for routing and reassembly on the Internet.

Redundancy

The inclusion of extra components or paths to mitigate failure and ensure a system is fault-tolerant.

Fault-Tolerant

The ability of a system to support failures and still continue to function.

Sequential Computing

A computational model where operations are performed one at a time in order.

Parallel Computing

A computational model where a program is broken into multiple smaller sequential operations performed simultaneously.

Distributed Computing

A computational model in which multiple devices are used to run a program, allowing for the processing of much larger problems.

Digital Divide

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

Citizen Science

Scientific research conducted by distributed individuals who contribute data via their own computing devices.

Crowdsourcing

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

Creative Commons

A public copyright license that enables the free distribution of copyrighted work when the creator wants to give others the right to share and build upon it.

Open Source

Programs that are made freely available and may be redistributed and modified.

Personally Identifiable Information (PII)

Information about an individual that identifies, links, relates, or describes them, such as Social Security numbers or biometric data.

Multifactor Authentication

A method of access control requiring at least two pieces of evidence from different categories: knowledge, possession, or inherence.

Symmetric Key Encryption

An encryption approach involving one key for both encryption and decryption.

Public Key Encryption

An encryption approach pairing a public key for encryption and a private key for decryption.

Phishing

A technique that attempts to trick users into providing personal information to access sensitive online resources.

Keylogging

The use of a program to record every keystroke made by a user to gain fraudulent access to confidential information.

Rogue Access Point

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