Web Development
What Is Docker and Why Do We Need It?
Docker packages an application with everything it needs to run, so it runs the same on every machine. What a container actually…
Web Development
HTML, CSS and the pieces that turn code into a page people can visit. Build layouts that work on a phone, and understand what the front end and back end each do.
13 guides
Web Development
REST API Error Handling and Status Codes: Best Practices
Which status code for which failure, a consistent error body, what to log versus what to return, and the mistakes that make…
Web Development
Fixing CORS Errors in React and Node
A React app on port 3000 calling an Express API on 8080 hits CORS immediately. The server-side fix, the dev-server proxy, credentials,…
Web Development
CSS Grid vs Flexbox: When to Use Which
Flexbox lays out a line of items; Grid lays out a two-dimensional area. The rule that decides between them, side-by-side examples, and…
Web Development
What Is a CORS Error? Frontend or Backend Problem?
CORS errors come from the browser, are fixed on the server, and cannot be fixed in the frontend code. What the error…
Web Development
What Is an API? A Plain-English Explanation
An API is a set of requests one program agrees to answer for another. What that means in practice, how to read…
Web Development
Working with Databases: A Beginner’s Introduction
What a database is, the SQL you actually need, and the one rule about building queries that separates safe code from a…
Web Development
CSS Grid Explained
Grid lays out rows and columns at the same time. Here is the fr unit, repeat and auto-fit, named areas, and the…
Web Development
CSS Flexbox Explained
Flexbox lays items out in one direction. Once you understand the main axis, justify-content and align-items stop being guesswork — here is…
Web Development
Responsive Design Basics
How to make a page work on a phone: the viewport tag, mobile-first media queries, flexible units, and the four things that…
Web Development
CSS Basics Explained
Selectors, the box model, flexbox and grid — the four things that account for most of what you will do in CSS,…
Web Development
HTML Basics Explained
The HTML tags that actually matter, why semantic elements beat divs, how forms and links work, and the accessibility basics that take…
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Where to go next
Programming Basics
The ideas every language shares — variables, loops, functions and how a program actually runs.
17 guides
Python
Plain-English Python guides, from your first line of code to small programs that do real work.
72 guides
JavaScript
How JavaScript works in the browser, explained with short examples you can paste and run.
32 guides
Keep going — pick your next guide
The fastest way to improve is to read one guide, then build the thing it describes. Start with the basics, or jump straight to a project.