Vocab

Analog information: Continuous data that can take any value within a range. Examples include sound waves, temperature, and light intensity. Analog information is often represented using physical quantities and must be converted into digital form for processing by computers.

Bit: Short for "binary digit," a bit is the smallest unit of digital data and can have only one of two values: 0 or 1. It is the fundamental building block of all digital computing and data storage.

Byte: A group of 8 bits, commonly used as a unit of storage in digital systems. A byte can represent a single character in text (such as a letter or number) or other small pieces of data.

PandA: Stands for "Presence and Absence," referring to a binary system used to represent data using two distinct states (e.g., 1 and 0, on and off, or true and false). This concept is fundamental to digital computing and data representation.

Metadata: Data that provides information about other data. Examples include the author of a document, the resolution of an image, or the date and time a file was created. Metadata helps organize, manage, and retrieve data efficiently.

List: A collection of ordered elements that can store multiple values, typically of the same or different types. Lists are commonly used in programming and data structures to manage and process sets of related items.

HTML (HyperText Markup Language): The standard language used to create and structure webpages. It defines elements such as headings, paragraphs, links, images, and tables to be displayed in a web browser.

Absolute Path: A complete and fixed file or URL location that specifies the full directory structure or web address from the root. For example, /home/user/documents/file.txt or https://example.com/images/photo.jpg.

Relative Path: A file or URL location specified in relation to the current directory or document. For example, images/photo.jpg refers to a file within an images folder relative to the current working directory.

RGB (Red, Green, Blue): A color model used in digital imaging and displays where colors are created by combining red, green, and blue light at different intensities.

Pixel (Picture Element): The smallest unit of a digital image or display, representing a single point of color. Images are composed of thousands or millions of pixels.

Intensity: The strength or amount of light emitted or displayed in a pixel. Higher intensity values produce brighter images.

Brightness: The overall lightness or darkness of an image, determined by the intensity of its pixels.

Contrast: The difference between the darkest and brightest parts of an image. Higher contrast makes details stand out more, while lower contrast makes an image appear washed out.

Frequency: The number of occurrences of a repeating event per unit of time. In digital media, it often refers to sound wave frequency (measured in hertz, Hz) or spatial frequency in images.

Sample: A data point taken from an analog signal during the process of digitization. In audio, a sample represents a snapshot of a sound wave at a given moment.

Sampling Rate: The number of samples taken per second when converting an analog signal to digital form. Measured in hertz (Hz), common values include 44.1 kHz for audio CDs.

Run-Length Encoding (RLE): A form of data compression that replaces consecutive repeated values with a count and the repeated value. For example, AAAAABBB would be encoded as 5A3B.

Nyquist Rule: A principle stating that to accurately digitize a signal, the sampling rate must be at least twice the highest frequency present in the signal. This prevents aliasing.

Lossy Compression: A method of reducing file size by permanently removing some data, often used in images (JPEG), audio (MP3), and video formats. It results in some loss of quality.

Lossless Compression: A method of reducing file size without losing any original data, often used for text, data files, and some image formats (PNG, FLAC). The original file can be perfectly reconstructed.

Latency: The delay between input and output in a system, such as the time it takes for data to travel over a network or for audio to be processed. Measured in milliseconds.

Bandwidth: The maximum amount of data that can be transmitted over a network connection in a given period, usually measured in bits per second (bps). Higher bandwidth allows for faster data transfer.

CSS (Cascading Style Sheets): A stylesheet language used to control the visual presentation of HTML elements, including layout, colors, fonts, and spacing.

CSS Property: A specific style rule applied to an HTML element, such as color, font-size, or margin.

CSS Value: The assigned setting for a CSS property, such as red for color or 16px for font-size.

CSS Selector: A pattern used to target HTML elements for styling, such as p (all paragraphs), #id-name (specific ID), or .class-name (elements with a class).

Padding: The space between an element’s content and its border, defined using CSS.

Table: An HTML structure used to display data in rows and columns, created with <table>, <tr> (rows), and <td> (cells).

List: A collection of items presented in an ordered (<ol>) or unordered (<ul>) format in HTML.

Client: A device or application that requests and receives data from a server, such as a web browser accessing a website.

Server: A computer or system that provides resources, services, or data to clients over a network.

Cookies: Small text files stored on a user's device by a web browser, used for tracking, authentication, and personalization.

IP Address (Internet Protocol Address): A unique numerical identifier assigned to devices on a network, such as 192.168.1.1.

Packet: A small unit of data transmitted over a network, containing source and destination information.

TCP/IP Protocol (Transmission Control Protocol/Internet Protocol): The fundamental set of rules governing how data is transmitted and received across the internet.

WAN (Wide Area Network): A large network covering a broad geographical area, such as the internet.

LAN (Local Area Network): A network connecting devices within a limited area, such as a home, school, or office.

Ethernet: A wired networking technology used to connect devices in a LAN using cables.

Wireless Network: A network that connects devices without cables, using Wi-Fi or other wireless protocols.

Router: A device that directs data packets between networks, such as connecting a home network to the internet.

Modem: A device that converts digital data into signals for transmission over a communication medium, such as DSL or cable.

ISP (Internet Service Provider): A company that provides internet access to users, such as Comcast or AT&T.

DNS (Domain Name System): A system that translates human-readable domain names (e.g., google.com) into IP addresses.

Redundancy: The inclusion of extra components or paths in a system to ensure reliability in case of failure.

Caching: The temporary storage of frequently accessed data to improve performance and reduce load times.

WWW (World Wide Web): The collection of interlinked websites and online resources accessed via the internet.

HTTP (HyperText Transfer Protocol): The protocol used for transmitting web pages over the internet.

URL (Uniform Resource Locator): The address of a web resource, such as https://www.example.com.

Search Engine: A web-based tool that indexes and retrieves information from the internet, such as Google or Bing.

Web Crawler (Spider): An automated program used by search engines to scan and index web pages.

Boolean: A data type that represents two values: true or false, often used in logical operations.

Logical Operators: Symbols or words used in Boolean logic, such as AND, OR, and NOT, to refine searches or conditions.

SSL/TLS (Secure Sockets Layer/Transport Layer Security): Cryptographic protocols used to encrypt data for secure internet communication.

PageRank: An algorithm developed by Google to rank web pages based on relevance and link authority.

Algorithm: A step-by-step set of instructions or rules designed to solve a problem or perform a task. Algorithms are used in programming to process data and make decisions.

Abstraction: The process of simplifying complex systems by focusing on essential details while ignoring unnecessary ones. In computing, abstraction allows programmers to manage complexity by working with high-level concepts rather than low-level details.

Program: A set of instructions written in a programming language that a computer can execute to perform a specific task.

Hardware: The physical components of a computer system, such as the CPU, RAM, hard drive, and peripherals like a keyboard or monitor.

Software: The programs and operating systems that run on a computer, enabling it to perform tasks. Software can be system software (e.g., Windows, macOS) or application software (e.g., web browsers, word processors).

Feedback: Information returned to a system or user about an action or process. In computing, feedback helps users understand system behavior, such as error messages or visual responses to user input.

Instance: A specific occurrence of an object or structure in computing. For example, an instance of a class in programming is a concrete object created based on that class.

Consistent Interface: A user interface design principle that ensures similar interactions across different applications or devices, making software easier to learn and use.

Metaphor: A design concept where familiar real-world objects or experiences are used to represent digital interactions, such as a folder icon for file storage or a trash bin for deleting items.

CPU (Central Processing Unit): The "brain" of the computer, responsible for executing instructions, performing calculations, and managing tasks.

ALU (Arithmetic Logic Unit): A component of the CPU that performs arithmetic and logical operations, such as addition, subtraction, and comparisons.

PC (Program Counter): A register in the CPU that keeps track of the next instruction to be executed in a program.

I/O (Input/Output): The communication between a computer and external devices, such as keyboards, monitors, printers, and storage drives.

Compiler: A program that translates source code written in a high-level programming language into machine code (binary) that a computer can execute.

RAM (Random Access Memory): A type of fast, temporary memory that stores data and programs currently in use. RAM is volatile, meaning it loses data when the computer is turned off.

Peripheral: An external device connected to a computer, such as a keyboard, mouse, printer, or external hard drive.

Secondary Storage (HDD vs SSD):

• HDD (Hard Disk Drive): A traditional storage device that uses spinning magnetic disks to store data. It is slower but offers larger storage capacity at a lower cost.

SSD (Solid State Drive): A modern storage device that uses flash memory, offering much faster speeds and improved durability compared to HDDs, but often at a higher cost.