AP Comp Sci Principles

Bit

• A contraction of “Binary Digit”

• The single unit of information in a computer

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

• Value is rounded

Analog Data

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

• Ex: music, colors of a painting, or position of a sprinter during a race

Digital Data

Data that changes discreetly 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

• Reversible

Lossy Compression

• A process for reducing the number of bits needed to represent something in which some information is lost or thrown out

• Not reversible

Binary

A way of representing information using only two options

Creative Commons

A collection of public copyright licenses that enable the free distribution of an otherwise copywriter work, used when an author wants to give people the right to share, use, and build upon a work that they have created

Data Compression

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

Decimal

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

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.

Open Access

Online research output free of any and all restriction on access and free of many restrictions on use license restrictions

Open Source

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

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 (IPP)

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

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

• Important because elements of complex systems like a computer network fail at unexpected times, often in groups

HTTP

• HyperText Transfer Protocol

• The protocol used for transmitting web pages over the Internet

Internet

A computer network consisting of interconnected networks the use standardized, open communication protocols

Packet

• Chunk of data sent over a network

• Larger messages are divided into packets that may arrive at a destination in order, out-of-order, or not at all

Packet Metadata

Data added to packets to help route them through the network and reassemble the original message

Routing

The process of finding a path from sender to receiver

UDP

A protocol used on the internet for fast transmission of information but with minimal error checking

World Wide Web

A system of linked pages, programs, and files

Router

A type of computer that forwards data across a network

Certificate Authority

Issue digital certificates that validate the ownership of encryption keys used in secure communications and are based on a trust model

Digital Divide

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

Debugging

Finding and fixing problems in an algorithm or program

Development Process

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

• Typical phases include investigating, designing, prototyping, and testing

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

Incremental Development Process

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

Iterative Development Process

A design approach requires refinement and revision based on feedback, testing, or reflection throughout the process

Program Requirements

Descriptions of how a program functions and may include a description of user interactions that a program must provide

Program Specification

A description of all the requirements for the program

Design Specifications

Describing the requirements for how a program will work or users will interact with it

Strings

An arbitrary length sequence of ASCII characters

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

Boolean Value

A data type that is either true or false

Comparison Operators

Indicate a Boolean Expression

Function

A named group of programming instructions

Function Call

A command that executes the code within a function

Arithmetic Operator

Part of most programming languages and includes addition, subtraction, multiplication, division, and modulus operators

Boolean Expression

Evaluates to either true or false

Concatenation

Joins together two or more strings end-to-end to make a new string

Conditional Statement

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

Evaluate

Expressions are evaluated to produce a single value

Expression

A programming statement that can consist of a value, a variable, an operator, or a procedure call that returns a value

Logical Operator

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

Procedure

Used to test the relationship between two variables, expressions, or values

Selection

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

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 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 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

Append

Add elements to the end of a list

Data Abstraction

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

Loops

Change the sequential flow of control by repeating a set of statements zero or more times, until a stopping condition is met

Logic Error

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

Simulation

Abstractions of more complex objects or phenomena for a specific purpose

Substring

Part of an existing string

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 the data; this process repeats until the desired value is found or all elements have been eliminated

Sequential Computing

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

Parallel Computing

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

Distributed Computing

A model in which programs are run by multiple devices

Parameter

A variable in a function definiton

Argument

The value passed through the parameter