Glossary

A Aspect ratio Aspect ratio is the proportion of an image's width to its height, such as… B Basal Metabolic Rate (BMR) Basal metabolic rate (BMR) is the energy your body uses at complete rest to… B Base32 Base32 encodes binary data using 32 characters, the capital letters A-Z and the digits… B Base58 Base58 is a text encoding that uses letters and digits but leaves out look-alike… B Base64 Base64 is an encoding that writes binary data using 64 printable characters (A-Z, a-z,… B Bit and byte A bit is a single 0 or 1. A byte is 8 bits. Network… B Body Mass Index (BMI) Body mass index (BMI) is your weight in kilograms divided by your height in… B Box shadow The CSS box-shadow property draws a shadow around an element using a horizontal and… C Caesar cipher A Caesar cipher replaces each letter with the one a fixed number of places… C CIDR notation CIDR notation writes an IP address followed by a slash and the number of… C Contrast ratio (WCAG) Contrast ratio compares the brightness of text and its background on a scale from… C CSS gradient A CSS gradient is a smooth blend between two or more colours drawn by… C CSV CSV (comma-separated values) is a plain-text table format: one row per line, with columns… E EXIF data EXIF is metadata stored inside a photo file: the camera model, the date and… F Favicon A favicon is the small icon shown in browser tabs, bookmarks and search results… G GCF and LCM The greatest common factor (GCF) is the largest whole number that divides two numbers… G GPA Grade point average (GPA) is the average of your course grades converted to points… H Hexadecimal Hexadecimal is a base-16 number system that uses the digits 0-9 and the letters… H HSL HSL describes a colour by hue (its position on the colour wheel in degrees),… H HTML entity An HTML entity is a code that stands for a character, written as an… I IPv4 address An IPv4 address is a 32-bit number written as four decimal values from 0… J JSON JSON (JavaScript Object Notation) is a lightweight text format for structured data made of… L Lossy and lossless compression Lossless compression shrinks a file and can restore it exactly. Lossy compression shrinks it… M Meta description A meta description is a short summary of a page, placed in the page's… M Minification Minification removes characters that are only there for people, such as spaces, line breaks… O Open Graph Open Graph is a set of meta tags, started by Facebook, that tells social… R RGB RGB describes a colour by how much red, green and blue light it contains,… r robots.txt robots.txt is a plain text file at the root of a website that asks… S Scientific notation Scientific notation writes a number as a value between 1 and 10 multiplied by… S SERP A SERP, or search engine results page, is the page a search engine shows… S Standard deviation Standard deviation measures how spread out a set of numbers is around its mean.… S Structured data (JSON-LD) JSON-LD is a way of adding structured data to a web page as a… T Token (LLM) A token is a chunk of text, often part of a word, that a… T Total Daily Energy Expenditure (TDEE) Total daily energy expenditure (TDEE) is the total number of calories you burn in… U URL encoding (percent-encoding) URL encoding, also called percent-encoding, writes characters that are not safe in a web… U URL slug A URL slug is the readable last part of a web address that identifies… W Well-formed XML Well-formed XML follows the basic syntax rules: one root element, properly nested and closed…