AP Computer Science Principles Vocabulary

a way of representing information using only two options.

a way of representing information using ten options.

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

8 bits

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

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

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

data that changes discretely through a finite set of possible values

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

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

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.

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.

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 have created.

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

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

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

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

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

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

the unique number assigned to each device on the Internet.

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

a type of computer that forwards data across a network

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.

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.

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.

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

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

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

a system of linked pages, programs, and files.

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

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.

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.

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.

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

a collection of program statements. Programs run (or “execute”) one command at a time.

program statements run in order, from top to bottom.

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

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

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

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

finding and fixing problems in an algorithm or program.

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

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.

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

allows a program to change the value represented by a variable

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

an ordered sequence of characters.

a data type that is either true or false.

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

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

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

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

a command that executes the code within a function.

data about data

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.

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

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

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

the collection of facts and patterns extracted from data

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

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

an ordered collection of elements

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

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

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

occurs when the ending condition will never evaluate to true.

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

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

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

the value passed to the parameter

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.

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

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

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

the subdivision of a computer program into separate subprograms.

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).

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

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

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

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

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

a process of encoding messages to keep them secret, so only "authorized" parties can read it.

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

involves one key for both encryption and decryption.

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

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

protects a computing system against infection.

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

a finite set of instructions that accomplish a task.

putting steps in an order.

deciding which steps to do next.

doing some steps over and over

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

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.

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.

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

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

provides a "good enough" solution to a problem when an actual solution is impractical or impossible

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

a problem with the goal of finding the "best" solution among many (e.g., what is the shortest path from A to B?)