APCSP

Binary

A way of representing information using only two options.

Bit

A contraction of 'Binary Digit'; the single unit of information in a computer, typically represented as a 0 or 1.

Byte

8 bits.

Overflow Error

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

Round-off Error

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

Analog Data

Data with values that change continuously, or smoothly, over time.

Digital Data

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

Sampling

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

Lossless Compression

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

Computing Device

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

Computing System

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

Computing Network

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

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

The unique number assigned to each device on the Internet.

Internet Protocol (IP)

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.

Packet

A chunk of data sent over a network.

Redundancy

The inclusion of extra components so that a system can continue to work even if individual components fail.

Fault Tolerant

Can continue to function even in the event of individual component failures.

HTTP

HyperText Transfer Protocol - the protocol used for transmitting web pages over the Internet.

Internet

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

World Wide Web

A system of linked pages, programs, and files.

Digital Divide

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

User Interface

The inputs and outputs that allow a user to interact with a piece of software.

Input

Data that are sent to a computer for processing by a program.

Output

Any data that are sent from a program to a device.

Program Statement

A command or instruction.

Program

A collection of program statements.

Sequential Programming

Program statements run in order, from top to bottom.

Event Driven Programming

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

Documentation

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

Comment

Form of program documentation written into the program to be read by people.

Pair Programming

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

Debugging

Finding and fixing problems in an algorithm or program.

Development process

The steps or phases used to create a piece of software.

Event

Associated with an action and supplies input data to 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.

Variable

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

String

An ordered sequence of characters.

Boolean Value

A data type that is either true or false.

Comparison Operators

<, >, <=, >=, ==, != indicate a Boolean expression.

Logical operator

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

Conditional Statement

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

Function

A named group of programming instructions.

Function Call

A command that executes the code within a function

List

An ordered collection of elements

Element

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

Index

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

Iteration

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

Infinite loop

Occurs when the ending condition will never evaluate to true

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

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

Selection

Deciding which steps to do next

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 elements have been eliminated

Reasonable Time

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

Unreasonable Time

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

Heuristic

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

Decision Problem

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

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?)

Undecidable Problem

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

Sequential Computing

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

Parallel Computing

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

Distributed Computing

A model in which programs are run by multiple devices

Speedup

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

Parameter

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

Argument

The 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

A process and allows a procedure to be used only knowing what it does, not how it does it

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

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

Cleaning Data

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

Correlation

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

Crowdsourcing

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

Information

The collection of facts and patterns extracted from data

Data bias

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

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

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)

Personally Identifiable Information (PII)

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

Phishing

A technique that attempts to trick a user into providing personal information

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

Malware

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

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

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