Glossary
Short, plain-English definitions of the terms you will meet while learning.
47 terms
- Algorithm
- A step-by-step set of instructions for solving a problem.
- dsa
- API
- Application Programming Interface. A set of rules that lets one program talk to another.
- javascriptnodejs
- Argument
- The actual value you pass into a function when you call it.
- javascriptpython
- Array
- An ordered list of values, each found by its position (index).
- javascriptdsa
- Attribute
- Extra information inside an HTML tag, written as name="value".
- html
- Big-O
- A way to describe how the work an algorithm does grows as its input grows.
- dsa
- Boolean
- A value that is either true or false.
- javascriptpython
- Class (CSS)
- A reusable label you put on elements so a CSS rule can target them, written .name.
- csshtml
- Component
- A reusable piece of a user interface, written as a function that returns JSX.
- react
- Condition
- An expression that is either true or false, used to decide which code runs.
- javascriptpython
- Console
- A place where a program prints messages so you can see what it is doing.
- javascriptpythonnodejs
- const
- A JavaScript keyword that creates a variable that cannot be re-assigned.
- javascript
- CSS
- Cascading Style Sheets. The language that controls how HTML looks.
- css
- DOM
- Document Object Model. The browser's live, changeable version of your HTML page.
- javascriptjquery
- Element
- An opening tag, its content and its closing tag, taken together.
- html
- Event
- Something that happens that code can react to, such as a click or key press.
- javascriptjqueryreact
- Flexbox
- A CSS layout system that lines items up in a row or column and spaces them out.
- css
- Float
- A number with a decimal point, such as 3.14.
- python
- Function
- A named, reusable block of code that can take inputs and return a result.
- javascriptpython
- Hash map
- A data structure that stores key-value pairs and finds a value by its key very quickly.
- dsa
- Hook
- A React function, such as useState, that lets a component use features like memory.
- react
- HTML
- HyperText Markup Language. The language that labels the parts of a web page.
- html
- HTTP
- The set of rules browsers and servers use to send requests and responses.
- nodejsjavascript
- Index
- The position of an item in an array or list. Counting starts at 0.
- javascriptpythondsa
- Integer
- A whole number with no decimal part, such as 7 or -3.
- python
- jQuery
- A JavaScript library with short commands for selecting and changing page elements.
- jquery
- JSON
- A plain-text format for data using curly braces, keys and values.
- javascriptnodejs
- JSX
- HTML-like syntax written inside JavaScript, used to describe React interfaces.
- react
- Library
- Pre-written code you include in your project to avoid writing everything yourself.
- jqueryreact
- Linked list
- A chain of nodes where each node holds a value and a link to the next one.
- dsa
- Loop
- Code that repeats an action until a condition says to stop.
- javascriptpython
- Module
- A file of code that shares some of its contents so other files can import them.
- javascriptnodejspython
- Node.js
- A program that runs JavaScript outside the browser, for servers and tools.
- nodejs
- npm
- Node Package Manager. The tool that downloads and manages JavaScript packages.
- nodejs
- Parameter
- A named placeholder in a function definition for a value that will be passed in.
- javascriptpython
- Props
- Inputs passed from a parent React component to a child component.
- react
- Queue
- A first-in, first-out collection: items leave in the order they arrived.
- dsa
- Recursion
- When a function solves a problem by calling itself on a smaller version of it.
- dsapythonjavascript
- Request
- A message a client sends to a server asking for something.
- nodejsjavascript
- Response
- The message a server sends back after a request.
- nodejsjavascript
- Selector
- A pattern that picks which elements a CSS rule or jQuery command applies to.
- cssjquery
- Stack
- A last-in, first-out collection: the newest item is the first to leave.
- dsa
- State
- Data a React component remembers between renders, which can change over time.
- react
- String
- A piece of text, written inside quotes.
- javascriptpython
- Tag
- A word in angle brackets, like <p>, that tells the browser what kind of content comes next.
- html
- Tree
- A structure of nodes connected from a single root, where each node can have children.
- dsa
- Variable
- A name that holds a value so you can use and change it later.
- javascriptpython