Study for AP Comp Sci

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

Process for creating a digital representation of analog data by measuring at regular intervals

Lossless Compression

Reduces bits without losing information; reversible

Lossy Compression

Reduces bits by losing some information; not reversible

Keyword Compression

Substitutes symbols or abbreviations for repeated words; lossless

Indexed Color Compression

Represents colors with numbers like paint-by-number; lossless

Run-Length Encoding

Stores counts of repeated pixels; lossless

JPEG Image Compression

Image compression that removes data not noticeable to the human eye; lossy

Intellectual Property

Creative work or invention protected by law

Creative Commons

Public licenses that allow sharing and reuse of creative work

Computing Device

Machine that runs a program

Computing System

Group of devices and programs working together

Computing Network

Group of interconnected computing devices

Path

Series of connections between sender and receiver

Bandwidth

Maximum data sent in a given time

Protocol

Set of rules for communication between systems

IP Address

Unique number assigned to each Internet device

Internet Protocol (IP)

Protocol for sending data using IP addresses

Router

Device that forwards data across a network

Packet

Small chunk of data sent over a network

Redundancy

Extra components or paths added for reliability

Fault Tolerant

Continues working despite failures

HTTP

HyperText Transfer Protocol for transmitting web pages

Domain Name System (DNS)

Translates domain names into IP addresses

Internet

Global network of interconnected networks

World Wide Web

Linked pages and resources accessed via the Internet

Digital Divide

Unequal access to technology

User Interface

Inputs and outputs for user interaction

Input

Data sent to a computer for processing

Output

Data sent from a program to a device

Program Statement

Single instruction in a program

Program

Collection of program statements

Sequential Programming

Code runs in order from top to bottom

Event Driven Programming

Code runs in response to events

Documentation

Written explanation of how code works

Comment

Notes in code for humans only

Pair Programming

Two programmers working together

Debugging

Finding and fixing errors

Development Process

Steps used to create software

Event

Action that triggers code execution

Expression

Values and operators that evaluate to one value

Assignment Operator

Changes a variable’s stored value

Variable

Named reference to a value

String

Sequence of characters

Boolean Value

Data type with true or false

Comparison Operators

Operators that compare values

Logical Operators

NOT, AND, OR

Conditional Statement

Code that runs based on a condition

Function

Named set of instructions

Function Call

Command that runs a function

Metadata

Data that describes other data

Citizen Science

Research involving public participation

Cleaning Data

Making data consistent without changing meaning

Correlation

Relationship between variables

Crowdsourcing

Gathering data from many people online

Information

Patterns and facts derived from data

Data Bias

Data that misrepresents a population

Data Filtering

Selecting specific data for analysis