Docker: the difference between an image and a container, explained with commands
What a Docker image is, what a container is and how they relate, with the basic commands to create, list, stop and remove each one, plus the most frequent mistakes.
Category
Web development
This category gathers articles about the technologies the web is built with: HTML and CSS for structure and presentation, JavaScript for interactivity, and the surrounding ecosystem (WordPress, APIs, Git, Docker and Linux).
Each article starts from a concrete problem, shows code you can copy and run, and links to the official documentation so you can dig deeper.
- HTML
- CSS
- JavaScript
- WordPress
- APIs
- Git
- Docker
- Linux
Articles in Web development
How to undo the last commit in Git without losing work
How to undo the last commit in Git with reset, revert and amend, which one to use when the commit is already pushed, and how to recover a commit you thought lost.
How to convert images to WebP (and when not to)
What WebP is, how much it saves over JPEG and PNG, how to convert images in the browser, the terminal or Node.js, and how to serve them with picture.
Lazy loading images in HTML: loading="lazy", fetchpriority and decoding
How to enable deferred image loading with loading="lazy", why you must not apply it to the main image, and how to combine it with fetchpriority and decoding.
WCAG colour contrast: how it is calculated, which ratios it requires and how to meet them
What the contrast ratio is, how it is calculated from luminance, what levels AA and AAA require, how to measure it and the design mistakes that fail it.
Which favicon sizes a website needs today (and which ones it no longer does)
The five favicon files needed in 2026 (ICO, SVG, apple-touch-icon and manifest icons), what Google requires to show it in results and which tags go in the head.