AP CS Principles Semester 1 Vocabulary

Simulation

A representation of a situation or problem with a similar but simpler model or a more easily manipulated model in order to determine experimental results.

Decimal

A system for representing numbers using combinations of the digits 0 - 9

Substring

Part of an existing string.

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 term-20unexpected times, often in groups

Certificate Authorities

trusted entities that verify identities of websites and issue certificates for them (like the DMV that issues driver's licenses)

World Wide Web

a system of linked pages, programs, and files

Router

a type of computer that forwards data across a network

Domain Naming System (DNS)

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

IP Address

the unique number assigned to each device on the internet

Uniform Resource Locator (URL)

the web address of the webpage being requested

Pseudocode

A notation resembling a simplified programming language, used in program design.

Index

A number used to access the elements in a list or string based on its position in the list.

Sampling

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

Data Compression

A process for reducing the number of bits needed to represent a piece of information

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.

Lossless Compression

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

Software

A program or a collection of programs.

Iteration

A repetitive portion of an algorithm which repeats a specified number of times or until a given condition is met. Also called a "loop" or "looping".

Pair Programming

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

Program

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

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 have created

Expression

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

Program Statement

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

Function Call

A command that executes the code within a function by using the function's given name with parentheses (ex: updateScreen( ) is a function call).

Program Specification

A complete description of how the program is specified to work. Sometimes referred to as the "Program Spec" or "Design Spec", it's usually a document that contains all of the requirements for the program.

Boolean Expression

A data type that evaluates to either true or false.

Boolean Value

A data type that is either true or false.

Program Requirement

A description of how a program or software feature should work. For example: "When the right-arrow button is selected on screen 1, the program should advance to screen 2".

Iterative Development Process

A design approach requires refinement and revision based on feedback, testing, or reflection throughout the process. This may require revisiting earlier phases of the process.

Incremental Development Process

A design approach that breaks the problem into smaller pieces and makes sure each piece works before adding it to the whole.

List

A generic term that refers to an ordered collection of elements. The AP CSP reference sheet uses this term instead of "array".

Data Abstraction (List)

A list is a type of data abstraction that helps manage complexity in a program because it simplifies the program code since the entire collection can be manipulated using the list name and an index.

While loop

A loop that continues to repeat while a condition is true.

For loop

A loop that has a predetermined beginning, end, and increment (step interval); should be used when the number of times the loop should execute is known before the program runs.

Watermark

A message (usually a logo, stamp, or signature) superimposed onto an image, with a great deal of transparency, usually included to imply ownership. Use of an image with a watermark can indicate a copyright violation.

Run-time Error

A mistake in the program that shows up when running the program.

Syntax Error

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

Function

A named group of programming instructions that may have parameters and return values. Also referred to as a "procedure".

Variable

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

Global Variable

A variable that can be used and updated by any part of the code; usually defined at the top of the program.

Local Variable

A variable that can only be seen, used, and updated within the function or onEvent where it is defined.

Binary

A way of representing information using only two options.

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.

Documentation

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

Append

Add an element to the end of a list.

Conditional Statement

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

Assignment Operator

Allows a program to change the value represented by a variable; in JavaScript, it's the equal symbol (=); in pseudocode it's the left pointing arrow (←).

Element

An individual item in a list that is assigned a unique position referred to by an index.

String

An ordered sequence of characters; in JavaScript, strings are always within double quotes.

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.

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.

Concatenation

The joining together of two or more strings end-to-end to make a new string; in JavaScript, the plus symbol is used to concatenate two strings together.

Comment

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

HyperText Transfer Protocol (HTTP)

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

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.

Digital Data

Data that changes discreetly through a finite set of possible values

Analog Data

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

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

Debugging

Finding and fixing problems in an algorithm or program.

Investigate and Reflect Phase

First step in the development process to decide on how the app will work and what it will do; get user input to help guide the program and UI design.

Procedure

The generic term for function; refers to a named block of code without implying any particular programming language. The AP CSP reference sheet uses the term PROCEDURE instead of function.

Modulus or MOD Operator

Is used to provide the remainder of a division problem as an integer value; for example, 22 MOD 7 is 1. In JavaScript, the percent symbol represents the MOD operator so 22 % 7 = 1.

Infinite Loop

Occurs when the loop goes on forever because the ending condition will never become true.

Open Access

Online research and resources free of any and all restrictions on access and free of many restrictions on use, such as copyright or license restrictions

Sequential Programming

Program statements that are run in order, from top to bottom.

Event Driven Programming

Program statements that run when triggered by an event, like a mouse click or a key press (in code.org, these are implemented as "onEvents").

Open Source

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

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.

Syntax Error

The code doesn't follow the rules of the programming language (usually generates a yellow triangle or red square in App Lab).

Logic Error

The code follows the rules of the programming language but doesn't function the way it's intended to.

Array

The name typically used in programming to refer to a list of items managed and accessible by a given list name.

Design Phase

The second step in the development process where a program or design specification is created that indicates how the program will work and/or how users will interact with it

Development Process

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

Coding Phase

The third step in the development process where the programmer writes the code and tests it as it's being developed (according to the design spec).

Plagiarism

The use of material created by someone else without permission and presented as one's own

Comparison Operators

These, <, >, <=, >=, ==, !=, are used to indicate a Boolean expression.

Logical Operator

These, NOT ( ! ), AND ( && ), and OR ( || ), evaluate to a Boolean value.

Protocol

a agreed-upon set of rules and standards that specify how devices on the internet communicate

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

Internet

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

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

Secure Sockets Layer (SSL) and Transport Layer Security (TLS)

a layer of security protecting your communications from snooping or tampering

Computing Device

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

Internet Protocol (IP)

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

User Datagram Protocol (UDP)

a protocol for sending packets quickly with minimal error-checking and no resending of dropped packets (faster than TCP)

Transmission Control Protocol (TCP)

a protocol for sending packets that does error-checking to ensure that all packets are received and properly ordered (more reliable than UDP)

Packet Metadata

data added to packets (like the IP address) to help route them through the network and reassemble the original message

Digital Divide

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

Digital Certificate

like an ID card to authenticate a website to prove that it is what it claims to be (like a driver's license from the DMV)

Web Browser

the app used to access webpages

Scalability

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

Internet Censorship

the control or suppression of what can be accessed, published, or viewed on the Internet enacted by regulators, or on their own initiative

Net Neutrality

the idea, principle, or requirement that Internet service providers should or must treat all Internet data as the same regardless of its kind, source, or destination

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

Bandwidth

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

Hyper Text Markup Language (HTML)

the programming language used to create and configure webpages

Path

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

Bit

the single unit of information in a computer, typically represented as a 0 or 1