apcsp vocab

Bit

a unit of information expressed as a 0 or 1

Byte

eight bits

Binary

A base 2 number system

Decimal

A base 10 number system

Overflow

when the value of a number stored in memory exceeds the maximum capacity of that memory

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 discretely 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. 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.

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

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.

Bandwidth

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

Computing Device

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

Computing Network

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

Computing System

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

Path

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

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

Protocol

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

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.

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

Router

A type of computer that forwards data across a network

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

Domain Name System (DNS)

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

HyperText Transfer Protocol (HTTP)

the protocol used for transmitting web pages over the Internet

World Wide Web

a system of linked pages, programs, and files

User Datagram Protocol (UDP)

Protocol used to send packets online. Does not do error checking.

Transmission Control Protocol (TCP)

Protocol used to send packets online. Does check that each packet arrives and puts them in the right order.

Scalable

Able to grow in size and still function well

Assignment Operator

allows a program to change the value represented by a variable

Expression

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

String

an ordered sequence of characters

Variable

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

Declare

Assign a section of memory to a name, creating a variable

Initialize

Assign an initial value to a variable

Boolean Value

a data type that is either true or false

Comparison Operator

Logical Operator

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

Conditional Statement

affects the sequential flow of control by executing different statements based on the value of 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

Information

the collection of facts and patterns extracted from data

Metadata

data about data

Cleaning Data

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

Data Filtering

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

Correlation

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

Citizen Science

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.

Crowdsourcing

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

Big data

extremely large and/or complex data sets that traditional data analysis tools and techniques cannot handle

Open data

data that is available to the general public

Data Bias

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

Machine learning

the use and development of computer systems that are able to learn and adapt without following explicit instructions, by using algorithms and statistical models to analyze and draw inferences from patterns in data.

Data Abstraction

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

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

List

an ordered collection of elements

Infinite Loop

occurs when the ending condition will never evaluate to true

Iteration

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

Traversal

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

Parameter

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

Argument

the value passed to the parameter

Return statement

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

Library

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

API

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

Procedural Abstraction

writing procedures so they can be used without the user knowing anything about how they work

Modularity

the subdivision of a computer program into separate subprograms

Computing Innovation

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).

Personally Identifiable Information (PII)

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

Keylogging

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

Malware

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

Phishing

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

Rogue Access Point

a wireless access point that gives unauthorized access to secure networks

Decryption

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

Encryption

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

Public Key Encryption

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

Symmetric Key Encryption

involves one key for both encryption and decryption

Computer Virus Scanning Software

protects a computing system against infection

Multi-factor Authentication

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

Algorithm

a finite set of instructions that accomplish a task

Problem

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

Selection

deciding which steps to do next

Sequencing

putting steps in an order

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

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

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

Decision Problem

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

Heuristic

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

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?)

Undecidable Problem

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

Distributed Computing

a model in which programs are run by multiple devices

Parallel Computing

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

Sequential Computing

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

Speedup

the time used to complete a task sequentially divided by the time to complete a task in parallel