Don’t know what a term means? Look it up here! All explanations are in plain English.

A way for programs to talk to each other. Like a waiter that takes your order (request) to the kitchen (server) and brings back your food (response).

A secret password that identifies you when using an API. Like a membership card at a club - you need it to get in.

The part of a website you don’t see - the server, database, and logic that runs behind the scenes. Like the kitchen of a restaurant.

A parallel version of your code. Like making a copy of a document to try changes without affecting the original.

The application you use to view websites (Chrome, Firefox, Safari, Edge). It reads HTML, CSS, and JavaScript and displays web pages.

A text-based way to interact with your computer. Instead of clicking buttons, you type commands. Claude Code runs in the CLI.

Copying a repository from GitHub to your computer. Like downloading a folder from the cloud.

Saving a snapshot of your code with a message explaining what changed. Like hitting “Save As” with a sticky note attached.

A tool in your browser that shows error messages and lets you run JavaScript. Open with F12 → Console tab.

The language that controls how websites look - colors, fonts, spacing, layouts. The “paint and decorations” of a web page.

Putting your website on the internet so others can see it. Like publishing a book after you’ve finished writing.

Built-in browser tools for debugging websites. Open with F12. Shows errors, lets you inspect elements, and more.

The address of a website (like google.com). Can be custom (yourname.com) or free (username.github.io).

A value stored outside your code, like passwords or API keys. Keeps secrets safe and makes code portable.

The part of a website you see and interact with - buttons, text, images. Like the dining area of a restaurant.

Software that tracks changes to your code over time. Like “Track Changes” in Word, but much more powerful.

A website that hosts Git repositories online. Like Google Drive for code, with extra features for collaboration.

A free service that turns a GitHub repository into a live website. No server setup required!

Where your website lives on the internet. The computer (server) that sends your website to visitors’ browsers.

The language that defines the structure of web pages - headings, paragraphs, images, links. The “skeleton” of a website.

A fancy text editor designed for writing code. VS Code is a popular example. Has features like syntax highlighting and auto-complete.

A programming language that makes websites interactive - animations, form validation, dynamic content. The “behavior” of a website.

A format for storing and sending data. Looks like this: {"name": "John", "age": 25}. Easy for both humans and computers to read.

Your own computer. “Running locally” means running on your machine, not on the internet. localhost is the address (usually http://localhost:3000).

An AI trained on lots of text that can understand and generate language. Claude is an LLM.

A simple way to format text using symbols. Like this: **bold**, *italic*, # Heading. Used in README files and documentation.

A program that lets you run JavaScript outside of a browser. Needed for development tools and servers.

A tool for downloading and managing JavaScript packages (reusable code). Comes with Node.js.

Software whose code is publicly available. Anyone can view, use, and often contribute to it. GitHub hosts lots of open source projects.

A reusable bundle of code someone else wrote. Like a pre-built component you can add to your project instead of building from scratch.

The location of a file or folder. Like an address: /Users/john/projects/my-site/index.html

The live version of your website that real users see. As opposed to development (what you’re working on locally).

Uploading your commits to GitHub. Like syncing your changes to the cloud.

Downloading changes from GitHub to your computer. Like syncing updates from the cloud.

A folder tracked by Git. Contains your project files and their history. Can be local (on your computer) or remote (on GitHub).

A website that adapts to different screen sizes - looking good on phones, tablets, and desktops.

A computer that stores websites and sends them to browsers when requested. GitHub Pages uses servers, so you don’t have to manage one.

A secure way to connect to servers and GitHub. Uses cryptographic keys instead of passwords. More advanced than HTTPS.

A website made of fixed files (HTML, CSS, JS, images) that don’t change. As opposed to dynamic sites that generate content on the fly.

The application where you type commands. Called “Command Prompt” on Windows, “Terminal” on Mac. Claude Code runs here.

A unit of text for AI models. Roughly 4 characters or 3/4 of a word. API pricing is based on tokens used.

A string of characters that proves your identity. Like a temporary password. Used for GitHub and API access.

A web address. Like https://github.com/user/repo. The way browsers find websites.

A system for tracking changes over time. Git is version control software. Lets you go back to previous versions and collaborate with others.

A popular free code editor made by Microsoft. Has lots of extensions and features for developers.

A sequence of steps to accomplish something. Your Git workflow might be: edit → add → commit → push.

If there’s a term you don’t understand that’s not here, try:

• Asking Claude Code: “What does [term] mean?”
• Searching MDN Web Docs
• Googling “[term] explained simply”