APCS TERM TEST

Bit

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. Some examples of analog data include 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 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.

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 copyrighted 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 the digits 0

intellectual property

A work or invention that is the result of creativity, such as a piece of writing or 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 restrictions on access and free of many restrictions on use, such as copyright or 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 (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

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.

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 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 that use standardized, open (nonproprietary) communication protocols.

Packet

A chunk of data sent over a network. Larger messages are divided into packets that may arrive at the destination in order, out

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 (User Datagram Protocol)

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.

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

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.

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

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.

Program Statement

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

Program

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

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 and which do not affect how a program runs

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. 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 the whole.

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.

Plagiarism

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

Program Requirements

descriptions 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

Syntax Error

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

Software

A program or a collection of programs

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. Also referred to as a "procedure".

Function Call

a command that executes the code within a function

Arithmetic operator

part of most programming languages and include addition, subtraction, multiplication, division, and modulus operators

Boolean Expression

evaluates to either true or false

Concatenation

joins together two or more strings end

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

a named group of programming instructions that may have parameters and return values.

Relational operator

used to test the relationship between two variables, expressions, or values. A comparison using a relational operator evaluates to a Boolean value. For example: =, ≠, >, <, ≥, and ≤

Selection

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

String

an ordered sequence of characters.

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

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 (iteration statements)

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 unexpectedly.

Simulation

abstractions of more complex objects or phenomena for a specific purpose

Substring

part of an existing string

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.

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

Undecidable Problem

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

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

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?)