Glossary: Useful Definitions of Web-related Terms

This Glossary alphabetically lists the definition of important web technological terms like Git, GitHub, HTML, CSS, JavaScript, Recursion, and Data. Click any of the letters below to jump straight to the terms that begin with that letter.

A – BCDEFGHIJ – K – LMNOP – Q – RSTUVW – X – Y – Z

A

Absolute length units

Absolute length units are fixed standards of measurement. In other words, the size of things expressed in any of the absolute length units will never change — regardless of the medium used to display them.

Learn more…

Anchor (URL)

An anchor is a link to a specific part of the same file the URL references.

Learn more…

AND operator (JS)

The AND operator (&&) checks if all of its operands are true.

Learn more…

Annotation

Annotations (markup) are notes that get added to texts. So, for instance, HTML is an annotation language developers use to describe a web document.

Learn more…

apply()

apply() is one of JavaScript’s built-in methods that you can use to reassign a specific method from one object to a different one.

Learn more…

Argument (JS)

An argument is an optional value you may pass to a function’s parameter through an invocator.

Learn more…

arguments object (JS)

An arguments object is an array-like object built-in to every non–arrow function.

Learn more…

Arithmetic expression (JS)

Arithmetic expressions are those that express a numeric value.

Learn more…

Array-like object (JS)

An array-like object is an object that has only a few — not all — of the features of a regular JavaScript array.

Learn more…

Assignment expression (JS)

Assignment expressions are those that assign their evaluated value to a variable (or property).

Learn more…

ASYNC

ASYNC (asynchronous) means “not synchronous”.

Events are asynchronous if they do not need to wait for each other to complete their processing before another event’s execution begins.

In other words, when two events happen asynchronously, event B does not need to wait for event A to complete its processing before starting its own execution.

ASYNC (JS)

In JavaScript, ASYNC (asynchronous) programming refers to functions that run in their own timing — without waiting for each other to finish its execution first.

An example is the setTimeout() method that invokes its callback argument in a given time — irrespective of the ongoing execution of other functions.

Audio data

Audio data are the sound-recorded contents of a page, such as WAV, MP3, and AAC.

Learn more…

B

Base case

A base case is a code written to discontinue the re-invocation of a recursive function.

Learn more…

bind()

bind() is one of JavaScript’s built-in methods that you can use to reassign a specific method from one object to a different one.

Learn more…

Browser

A browser is a software application used to view a website’s content.

Learn more…

Build step

A build step is a process through which a bundler builds a new browser compatible JavaScript file.

C

call()

call() is one of JavaScript’s built-in methods that you can use to reassign a specific method from one object to a different one.

Learn more…

Chunk

A chunk refers to the modified section of a file.

A chunk consists of the modified line and its context, where context means some unaltered lines before and after the modified line.

Learn more…

Class component

A class component is a plain JavaScript Class that extends a user-defined class to the built-in React.Component class located inside the React library.

Learn more…

Code

code is any language that computers can understand and process.

Learn more…

Controlled component (ReactJS)

A controlled component is a component whose form’s data React controls exclusively.

Learn more…

Create React App

Create React App (CRA) is an official React package used to set up React projects easily without going through the troubles of configuring build tools like Webpack or Babel.

Learn more…

CSS

CSS (Cascading Style Sheets) is a styling language that styles elements of an HTML document.

Learn more…

CSS unit

A CSS Unit is the standard of measurement used in CSS to express the size of a specific element’s property.

Learn more…

D

Data

Data is the content of a document. In order words, the text and graphics on a page are the document’s data.

Learn more…

Deep copy (JS)

You do deep copy when you clone objects without creating references.

Learn more…

Deep object (JS)

A deep object is one that contains a non-primitive item.

Learn more…

Destructuring array (JS)

The destructuring array assignment is a unique technique you can use to copy an array’s value into new variables neatly.

Learn more…

Destructuring assignment (JS)

The destructuring assignment is a unique technique you can use to copy the values of an object or array into new variables.

Destructuring object (JS)

The destructuring object assignment is a unique technique you can use to copy an object’s values into new variables neatly.

Learn more…

Distribution code

A distribution code is the minified and optimized version of the source code. It is the distribution code (the build step’s output) that gets loaded to the browser.

DNS Hierarchy

DNS Hierarchy is a system used to sort the parts of a domain name according to their importance.

Learn more…

Document

A document is a page used to contain text, or graphics, or both.

Learn more…

Domain name

A domain name is a website’s name.

Learn more…

Domain Name Server

A Domain Name Server (DNS) is the server (or computer) used to store domain names and their corresponding IP addresses.

Learn more…

Domain Name System

A Domain Name System (DNS) is the system (technique) by which domain names get converted to their equivalent IP (Internet Protocol) addresses.

Learn more…

E

Editor

An editor is a person that edits a software document.

Learn more…

Editing platform

An editing platform (IDE) is the app used by editors (developers) to prepare documents for publication.

Learn more…

Effect hook (ReactJS)

The effect hook (useEffect) allows a function component to hook into React’s lifecycle features for performing side effects.

Learn more…

Entry point

An entry point is the most critical file of a build step that links (directly or indirectly) to every other module in the project.

Equality operator (JS)

The equality operator (==) checks if its two operands are of equal value.

Learn more…

Error handling phase (ReactJS)

A component’s error handling phase is the period when an error occurs in any of the following cases:

  • During the component instance’s rendering
  • In a lifecycle method of the component
  • In any child component’s constructor

Learn more…

Execution time

Execution time (also called runtime) is the time during which a program is running.

In other words, it is the execution period (or lifecycle phase) of a program — which begins from the time the program is invoked and ends when the program’s invocation is closed.

Expression (JS)

A JavaScript expression is any piece of code that expresses a value.

Learn more…

F

File path (URL)

A URL’s file path is the path (route) to a website’s resource on a web server.

Learn more…

Framework

A framework is a codebase written to serve as the primary structure for your application.

Learn more…

Function component

A function component is a regular JavaScript function that can accept a single properties object (props) as its parameter and emits a React element as its return value.

Learn more…

G

Git

Git is a Distributed Version Control System (DVCS) used to save different versions of a file (or set of files) — wherein any version is retrievable at will.

Git makes it easy to record and compare different file versions. Consequently, details about what changed, who changed what, or who initiated an issue are reviewable anytime.

Learn more…

GitHub

GitHub is a web-based platform for hosting (or sharing) Git repositories. It helps you facilitate easy sharing and collaboration on projects with anyone at any time.

GitHub also encourages broader participation in open-source projects by providing a secure way to edit files in another user’s repository.

Learn more…

Git cloning

Git Cloning is mainly about getting (downloading) a copy of a .git repository.

Learn more…

Git commit

Whenever you commit your files to Git, it means you have stored the staged version of your working directory’s file(s) into the .git repository.

Learn more…

Git directory

Git directory is a folder Git creates in the working directory you instructed it to monitor.

Learn more…

Git initialization

Initialization is to make Git ready to start monitoring files in a specified directory.

Learn more…

Git staging

Staging implies that you have added details about your staged file(s) into a file called “index” — located in the Git directory.

Learn more…

Git staging area

The staging area is a file Git uses to store details about files it is about to commit into the .git directory.

Learn more…

Graphical data

Graphical data are the visual contents of a page, such as diagrams, charts, videos, and images.

Learn more…

Greater than operator (JS)

The greater than operator (>) checks if its left operand is greater than its right-hand one. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

Greater than or equal to operator (JS)

The greater than or equal to operator (>=) checks if its left operand is greater than or equal to its right-hand operand. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

H

HTML

HTML (HyperText Markup Language) is an extension of plain texts. It is a note to browsers about a document’s data, thereby helping browsers present webpages accurately.

Learn more…

Hyper

Hyper means Extensive (that is, an extension of another thing).

Learn more…

HyperLink means ExtensiveLink (that is, a link that acts as an extension of another link).

Learn more…

HyperSpace

HyperSpace means ExtensiveSpace (that is, a space that acts as an extension of another space).

Learn more…

HyperText

HyperText means ExtensiveText (that is, a text that acts as an extension of another text).

Learn more…

I

Impure function

An impure function is a function that contains one or more side effects.

Learn more…

Internet

The internet is one of the means through which data gets shared between two or more computers.

Learn more…

Iterable

An iterable is an object that has a property with a @@iterator key.

Learn more…

J

JavaScript

JavaScript is a commanding language that commands the items of an HTML document.

Learn more…

JSX

JSX (JavaScript and XML) is a syntax extension to JavaScript that allows you to build React elements with HTML-like syntax right inside your JavaScript code.

Learn more…

L

Left-hand-side expression (JS)

Left-hand-side expressions are those on the left-hand side of an assignment operator and serve as the destination of the value expressed by the right-hand expression.

Learn more…

Less than operator (JS)

The less than operator (<) checks if its left operand is less than its right-hand one. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

Less than or equal to operator (JS)

The less than or equal to operator (<=) checks if its left operand is less than or equal to the one on the right-hand. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

Lexical

Lexical refers to the definition of things.

Learn more…

Lexical scope

Lexical scope is the definition area of an expression.

Learn more…

Lexicon

A lexicon is a dictionary where words are listed and defined.

Learn more…

Library

A library is a codebase written to act as an add-on feature to your application.

Learn more…

Lifecycle (ReactJS)

The lifecycle of a React component refers to the series of stages a component instance goes through from its creation to its total removal from the DOM.

Learn more…

Lifecycle methods (ReactJS)

Lifecycle methods are the inbuilt React methods you can use to operate on your components during their lifecycle in the DOM.

Learn more…

Logic (JS)

Logic is the analytical action performed by a computer, which often requires the computer to decide if a specific condition is true or false.

Learn more…

Logical expression (JS)

Logical expressions are those that express the Boolean values, true or false.

Learn more…

M

map() in JavaScript

map() creates a new array that contains the result of invoking map()‘s function argument on each item of the calling array.

Learn more…

Markup

Markup means Annotate (that is, a note added to a piece of writing). They are the part of an HTML text that tells browsers how they should display the text.

Learn more…

Method

A method is a function encased in a properties object as one of the object’s property’s values.

Minimax algorithm

A minimax algorithm is a recursive program written to find the best gameplay that minimizes any tendency to lose a game while maximizing any opportunity to win the game.

In other words, minimax is a recursive function created to help a player (the maximizer) decide on the gameplay that minimizes the maximum possibility to lose a game.

Learn more…

Mounting phase (ReactJS)

A component’s mounting phase is when the component instance is being created and rendered into the DOM.

Learn more…

Multi-page application

A multi-page application (MPA) is a web app in which each of its unique URL file paths refers to a brand-new HTML page that needs to be reloaded from the server each time users request the page.

Learn more…

N

Networking

Networking means connecting things.

Learn more…

Non-assignment expression (JS)

Non-assignment expressions are those that do not assign their evaluated value to any variable (or property).

Learn more…

Non-primitive data (JS)

Non-primitive data is any JavaScript value that can contain multiple other JavaScript values.

An object is the only non-primitive value in JavaScript. However, JavaScript objects are of four types: properties objects, array objects, function objects, and regular expression objects.

NOT equal to operator (JS)

The NOT equal to operator (!=) checks if its two operands are not of equal value. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

NOT operator (JS)

The NOT operator (!) is used to negate the Boolean value of an expression. In other words, it converts true to NOT true and false to NOT false.

Learn more…

NOT strictly equal to operator (JS)

The Not strictly equal to operator (!==) checks if its two operands are strictly not of equal type and equal value. If so, the Boolean value true gets returned. Otherwise, the computer will return false.

Learn more…

NPM

NPM (Node Package Manager) is a package manager (an alternative to Yarn) that automatically helps find and execute a specified package.

NPX

NPX is node’s package runner tool. It helps to automatically find and execute a specified package.

Nullish coalescing operator (JS)

The nullish coalescing operator (??) checks if its left-hand side operand is undefined or null. If so, it returns its right-hand side operand. Otherwise, it produces its left-hand side operand.

Learn more…

O

OR operator (JS)

The OR operator (||) checks and returns true if one (or both) of its operands is true. Otherwise, it returns false if both of its operands are false.

Learn more…

Output file

An output file is the compiled version of an entry file.

P

Parameter (URL)

A parameter (query string) allows you to send specific data to the server.

Learn more…

Port (URL)

A port is a technical gate on a website’s server from which browsers can access a site’s resources.

Learn more…

Primary expression (JS)

Primary expressions are those that serve as the basis of all other expressions.

Learn more…

Primitive data (JS)

Primitive data is any plain JavaScript value that you can use to program a webpage and its content.

A Primitive value is neither a property nor a method. Instead, it is a plain value that you can use in a property, method, variable, or function.

JavaScript has seven Primitive values: Number, String, Boolean, undefined, Null, Symbol, and BigInt.

Pure function

A pure function is a function without any side effects.

Learn more…

R

ReactJS

React is a component-based JavaScript library used to build user interfaces (UI) efficiently.

Learn more…

React component

A component is a JavaScript function (or class) that can accept arbitrary inputs (called “props”) and returns an element (UI).

Learn more…

React element

React element is the specific user interface (UI) you want to see displayed on-screen.

Learn more…

React hooks

React hooks are functions used in a function component to hook into React’s state object, lifecycle methods, and other React features without writing a class component.

Learn more…

React props

React props are parameters used to pass arguments to components.

Learn more…

React Router

React Router is a popular routing library that tells React the specific component it should render based on the route (file path) a user requested through the URL.

Learn more…

React setState()

setState() is the method used to update a class component’s state.

Learn more…

React state

React state is a built-in object used to store a component’s values that are likely to change over time.

Learn more…

Recursion

Recursion is a method by which a problem gets solved through iteration.

In other words, a recursive function is a function that repetitively invokes itself infinitely (or until something stops it).

Learn more…

Relative length units

Relative length units are dynamic units. In other words, the sizes of things expressed in any of the relative length units will always be dependent on another length.

Learn more…

Rest operator (JS)

The rest operator is used to put the rest of some specific user-supplied values into a JavaScript array.

Learn more…

Rest parameter (JS)

A JavaScript rest parameter consists of the rest operator and a regular parameter.

Learn more…

Rest variable (JS)

A JavaScript rest variable consists of the rest operator and a regular variable.

Learn more…

Root-level domain

The root-level domain (“”) is the highest hierarchy level of any domain name system.

Learn more…

Root directory

Root directory refers to the folder containing all other files and sub-folders of a specific project.

In other words, a root repository is a working directory that houses everything concerning a particular project.

Learn more…

Router

A router is a code logic used to handle a client’s request to a specific file path.

Learn more…

Runtime

Runtime (also called execution time) is the time during which a program is running.

In other words, it is the execution period (or lifecycle phase) of a program — which begins from the time the program is invoked and ends when the program’s invocation is closed.

S

Scheme (URL)

A scheme indicates the protocol (set of rules) browsers must use to access a website’s resources. Some popular schemes are HTTP, HTTPS, Mailto, and FTP.

Learn more…

Scope

Scope refers to the area where an item (such as a function or variable) is visible and accessible to other code.

Learn more…

Scope chain

A scope chain refers to the unique spaces that exist from the scope where a variable got called to the global scope.

Learn more…

Search engine

A search engine is a software program you can use to search for resources on the internet.

Learn more…

Server (Computing)

A server is a computer where documents (such as webpages, videos, audios, and images) are stored until other computers request them over the internet (or local network).

Learn more…

Shallow copy (JS)

You do shallow copy when you create references while cloning one object into another.

Learn more…

Shallow object (JS)

A shallow object is one that contains only primitive items.

Learn more…

Side effect

Side effect occurs in a program whenever you use an external code in your function—which, as a result, impacts the function’s ability to perform its task.

Learn more…

Single-page application

A single-page application (SPA) is a web app in which each of its unique URL file paths refers to a single HTML page that gets loaded only once from the server.

Learn more…

Source code

A source code is a code you write and edit.

Spread operator

The spread operator (...) helps you expand iterables into individual elements.

Learn more…

State

State is the specific data managed by a stateful program.

Learn more…

State hook (ReactJS)

The state hook (useState) allows a function component hook into React’s state object.

Learn more…

Stateful program

A stateful program is a program whose output depends on external states (events).

Learn more…

Stateless program

A stateless program is one whose output does not depend on any external event.

Learn more…

Strict equality operator (JS)

The strict equality operator (===) checks if its two operands are strictly of equal type and value.

Learn more…

Strict mode (JS)

JavaScript’s strict mode is a way of ensuring the code in a script (or function) are strictly JavaScript code — not generic code nor mistyped JavaScript code.

You can invoke the strict mode by including the literal string "use strict"; as the first statement of your script file (or function statement).

Learn more…

String expression (JS)

String expressions are those that express a string value.

Learn more…

Subdomain

A subdomain (third-level domain) is a subset of a specific website. It allows you to categorize your website into one or more sections.

Learn more…

T

Text

Text is any writing that is composed of characters.

Learn more…

Text Markup

Text Markup means Text Note (that is, the note added to a text to help typesetters (or computers) better understand how to present the marked-up text).

Learn more…

Textual data

Textual data are the written contents of a page, such as letters (e.g., A, B, C), numbers (e.g., 1, 2, 3), symbols (e.g., $, #, +), and code (e.g., <input>, body { background: #A18A77; }, if (condition) { //execute code }).

Learn more…

this (JS)

JavaScript’s this keyword refers to the owner object of the keyword’s method or the “this” value of an arrow function’s lexical context.

Learn more…

Top-level domain

The top-level domain (TLD) is what follows the domain name in a URL.

Learn more…

U

Uncontrolled component (ReactJS)

An uncontrolled component is a component whose form’s data React does not control exclusively.

Learn more…

Unit

A unit is anything accepted as a gauge for expressing the quantity or size of another thing.

Learn more…

Unmounting phase (ReactJS)

A component’s unmounting phase is when the component’s instance is being removed from the DOM.

Learn more…

Updating phase (ReactJS)

A component’s updating phase is the period when the component instance is being updated.

Learn more…

URL (Uniform Resource Locator)

A URL is a website’s specific location on a computer (web server).

Learn more…

V

Version Control System

A Version Control System (VCS) refers to the specific method employed to save a file’s versions for future references.

Learn more…

W

Webpage

A web page is a single code file configured by an editor to interconnect with other documents on the World Wide Web (WWW).

Learn more…

Website

A website is a set (or collection) of web pages configured by an editor to interconnect with other documents on the World Wide Web (WWW).

Learn more…

Web address

A web address (URL) is a website’s specific location on a computer (web server).

Learn more…

Working directory

A working directory is a local folder you create to store all your project’s files.

As such, any folder you create anywhere on a system is a working directory.

Learn more…

Workstation

A workstation is a powerful computer (or laptop) used for technical and engineering works like software development, computer-aided designs (CAD), and other graphics-intensive projects.

Learn more…

Y

Yarn

Yarn is a package manager (an alternative to NPM) that automatically helps find and execute a specified package.

Get Notified of the Latest Publications