APCSP (2025-2026)

decimal number

base 10 number with ten possible different digits (0-9)

binary number

base 2 number with two possible different digits (0-1)

bit

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

analog data

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

digital data

data that changes discreetly through a finite set of possible values

sampling

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

abstraction

reduces information and detail to facilitate focus on what is relevant
(It is a process, a strategy, and the result of reducing detail to focus on concepts relevant to understanding and solving problems.)

lossless compression

process for reducing the number of bits needed to represent something without losing any information

lossy compression

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

computing device

machine that can run a program

computing system

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

computing network

group of interconnected computing devices capable of sending or receiving data

path

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

bandwidth

maximum amount of data that can be sent in a fixed amount of time

protocol

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

IP address

unique number assigned to each device on the Internet

IP

protocol for sending data across the Internet that assigns unique numbers to each connected device

router

type of computer that forwards data across a network

redundancy

inclusion of extra components so that a system can continue to work even if individual components fail

fault tolerant

when something can continue to function even in the event of individual component failures

datastream

information passed through the internet in packets

packet

chunk of data sent over a network

packet metadata

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

TCP

(Transmission Control Protocol) protocol for sending packets that does error-checking to ensure all packets are received and properly ordered

UDP

(User Datagram Protocol) protocol for sending packets quickly with minimal error-checking and no resending of dropped packets

scalability

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

DNS

(Domain Name System) system responsible for translating domain names like example.com into IP addresses

World Wide Web

a system of linked pages, programs, and files

HTTP

protocol for computers to request and share the pages that make up the world wide web on the Internet

Digital Divide

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

UI

(user interface) the inputs and outputs that allow a user to interact with a piece of software

input

data that are sent to a computer for processing by a program

output

any data that are sent from a program to a device

statement

a command or line of instruction in a program

program

a collection of programming statements

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

debugging

the process of finding and fixing problems in code