AP COMP SCI (everything you need to know)

Analog Data

Data represented by continuous signals, such as sound or temperature, that can take on any value within a given range.

Digital Data

Data represented by discrete values, such as binary code, which can only take on specific, separate values.

Bit

The smallest unit of data in computing, represented as a 0 or a 1 in binary code.

Byte

A group of 8 bits that can represent 256 different values, commonly used to encode a single character of text in computer systems.

Binary

A numeric system that uses only two symbols, typically 0 and 1, to represent data in computing and digital systems.

Decimal

The number that is represented in the commonly used base ten system.

Abstraction

The process of reducing complexity by hiding the details of implementation while exposing only the necessary features. It allows programmers to focus on high-level functionality.

Sampling

The process of converting an analog signal into a digital signal by measuring the amplitude of the signal at discrete intervals.

Overflow Error

An error that occurs when a calculation exceeds the storage capacity of the variable type, often resulting in incorrect or unexpected values.

Round-off Error

An error that arises when a number is approximated to a certain number of decimal places, leading to a loss of precision in calculations.

Runtime Error

An error that occurs during the execution of a program, causing the program to terminate unexpectedly or behave incorrectly.

Logic Error

An error that occurs when a program runs without crashing but produces incorrect results due to flaws in the algorithm or logic used in the code.

Syntax Error

An error that occurs when the code does not conform to the grammatical rules of the programming language, preventing the program from compiling or running properly.

Lossy Compression

A data compression technique that reduces file size by permanently eliminating certain information, resulting in a loss of quality that cannot be restored.

Lossless Compression

A data compression technique that reduces file size without losing any information, allowing the original data to be perfectly reconstructed.

Metadata

Data that provides information about other data, such as its source, context, or formatting.

Computing Device

Any electronic device that processes data, typically including computers, smartphones, and tablets.

Computing Network

A group of interconnected computing devices that communicate and share resources with each other, facilitating data exchange and collaboration.

Computing System

A combination of hardware and software designed to execute tasks and process information, commonly involving a computer and its peripherals.

Path

The sequence of specified directories and files that a computer system uses to locate a resource, such as a file or executable program.

Bandwidth

The process of selecting paths in a network to send packets of data from source to destination, ensuring efficient data transfer across interconnected devices.

Protocol

A set of rules and conventions for communication between devices in a network, defining how data is transmitted and received.

Scalability

The capability of a system to handle a growing amount of work or its potential to be enlarged to accommodate that growth. It refers to the ability to scale up or scale down resources as needed.

Internet Protocol (IP)

A set of rules governing the format of data sent over the internet or local network, ensuring that messages are sent to the correct destination.

Data Stream

A continuous flow of data that is transmitted in a sequence, often used for real-time processing or transmission over a network.

TCP (Transmission Control Protocol)

A communication protocol that facilitates reliable, ordered, and error-checked delivery of data between applications running on hosts communicating via an IP network.

UDP (User Datagram Protocol)

A communication protocol used for establishing low-latency and loss-tolerating connections for applications that do not require reliable delivery of data.

Packets

Small units of data that are transmitted over a network, containing payload and control information for routing and delivery.

World Wide Web

A system of interlinked hypertext documents and multimedia content accessed via the internet, using browsers to navigate.

HTTP (Hypertext Transfer Protocol)

A protocol used for transferring hypertext via the internet, enabling web browsers to fetch and display web pages.

Fault Tolerance

The ability of a system to continue operating correctly in the event of a failure of some of its components. Fault tolerance is essential for maintaining service availability and reliability. R

Redundancy

the inclusion of extra components or systems to ensure operational continuity in case of failure.

Digital Divide

The gap between those who have easy access to digital technology and the internet and those who do not, often due to socioeconomic factors.

Creative Commons

A licensing framework that allows creators to grant permissions for the use of their work while retaining certain rights. Creative Commons licenses enable sharing and collaboration while protecting copyright.

Copyright

a legal framework that grants creators exclusive rights to their original works, allowing them to control the use, distribution, and reproduction of those works.

Open Source

Software that is freely available for use, modification, and distribution, promoting collaborative development and community engagement.

Peer to peer network

A decentralized network structure that allows direct sharing of resources, files, or information between users without the need for a central server.

Open Acess

a publishing model that allows free and unrestricted access to research outputs, making scholarly work available to everyone without subscription or payment.

Variable

A storage location in a program with a name that contains data which can change during program execution.

String

A sequence of characters used to represent text in programming, often enclosed in quotation marks.

Index

a data structure that improves the speed of data retrieval operations on a database or a collection of data.

Boolean

A data type that can hold one of two possible values: true or false, typically used for conditional statements and logic operations.

Iteration/Loop/Sequence

The process of repeatedly executing a set of instructions or statements in a program until a certain condition is met, often used in loops.

List/Array

A data structure that stores a collection of elements in a specific order, allowing for efficient access and modification of its items.

Data Abstraction

The concept of simplifying complex reality by modeling classes based on the essential properties and behaviors, allowing programmers to work with ideas rather than specific details.

Algorithm

A finite set of well-defined instructions designed to perform a specific task or solve a problem, typically expressed in a sequence.

Conditional/If statement/Selection

A programming construct that allows the execution of certain code blocks based on whether a specified condition is true or false.

Conditional Operators

Symbols that compare values and return a Boolean result, such as <, >, ==, and !=.

Logical Operators

Symbols used to connect multiple conditions, resulting in Boolean outcomes, such as AND, OR, and NOT.

Traversal

The process of visiting each node in a data structure, such as a tree or graph, in a systematic manner to perform an action or retrieve information.

Modulo/MOD

An arithmetic operation that finds the remainder when one integer is divided by another, commonly used in programming to determine even or odd numbers.

Interger

A data type that represents whole numbers, both positive and negative, without any fractional components. Integers are commonly used in programming for a variety of calculations.

Substring

A contiguous sequence of characters within a string, often used in programming to manipulate or analyze text data.

Procedure/Function

A block of code designed to perform a specific task, which can be executed when called in a program. Functions can accept inputs and return outputs, promoting code reuse.

Argument

A value passed to a procedure or function when it is called, allowing for dynamic input and making the function versatile. P

Parameter

A variable in a function definition that receives an argument passed to the function, allowing the function to utilize that value during execution.

Simulation

A model of a real-world system or process that is run on a computer to study its behavior under various conditions and input scenarios, often used in testing or training.

Element

An individual part of a data structure, such as an item in an array or a node in a linked list, which can be accessed and manipulated within algorithms.

Personally Identifiable Information (PII)

Information that can be used to identify an individual, such as names, social security numbers, or other personal details.

Multi factor Authentication

A security process that requires two or more forms of verification to gain access to a system, enhancing protection against unauthorized access.

Encyrption

The process of converting information or data into a code to prevent unauthorized access, ensuring confidentiality and security during transmission and storage. D

Decryption

The process of converting encrypted data back into its original format so that it can be understood and used. Decryption typically requires a key or password. S

Symmetric Key Encryption

A singular key is used for both the encryption and decryption of the message

Public Key Encryption

A cryptographic system that uses a pair of keys; one public key for encryption and a private key for decryption, ensuring secure communication over insecure channels.

Digital Certificates

Digital documents used to prove the ownership of a public key, often issued by a Certificate Authority, ensuring that the key belongs to the authentic entity.

Computer Virus

A malicious program designed to replicate itself by infecting other files or programs on a computer system. It can damage or disrupt computer operations.

Malware

Any software intentionally designed to cause damage to a computer, network, or server, including viruses, worms, and trojans.

Phishing

A cyber attack that uses deceptive tactics to trick individuals into revealing sensitive personal information, such as passwords or credit card numbers, often through fraudulent emails or websites.

Key Logging

The act of tracking the keystrokes made on a keyboard, often used to capture sensitive information such as passwords and credit card numbers.

Rouge Access Point

A malicious Wi-Fi access point set up to eavesdrop on wireless communications or gain unauthorized access to a network.

Crowd sourcing

The practice of obtaining information or services by soliciting contributions from a large group of people, often via the internet, to solve problems or gather data.

Citizen Science

The use of people to collect data based on community input

Parallel computing

A type of computation in which many calculations or processes are carried out simultaneously, leveraging multiple processors or computers to solve problems more efficiently.

Library

A collection of pre-written code or functions that can be reused to perform specific tasks in programming, enhancing efficiency and organization in software development.

Unsolvable Problems

Problems that cannot be solved by any algorithm or computational method, often due to inherent limitations in computation, such as the Halting Problem.