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
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.
9 guides
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…
Web Development
Web Development for Beginners: A Map of What to Learn
What HTML, CSS, JavaScript, the front end and the back end each do, how a page actually reaches your screen, and the…
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Where to go next
Programming Basics
The ideas every language shares — variables, loops, functions and how a program actually runs.
12 guides
Python
Plain-English Python guides, from your first line of code to small programs that do real work.
30 guides
JavaScript
How JavaScript works in the browser, explained with short examples you can paste and run.
16 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.