How To

The handshake is the moment two machines agree how to talk securely. Why it fails, what a visitor can fix, and the server settings behind most of them.

A page in Google Docs is not a thing you can delete, it is the result of what is on it. Five ways to remove one, including the stubborn blank last page.

Saving a GIF so it still moves depends on where it came from. The way that works on each device, and why some of them save a still picture instead.

setTimeout runs your code later, not exactly on time. How to use it, how to cancel it, and the five mistakes that make it behave strangely.

CSS is the part of a web page that decides how it looks. What it does, how it connects to HTML, and the three rules that explain most of it.

Three ways to make a CSV, and the settings that decide whether the other side can read it. Separator, encoding and the quoting rule that breaks imports.

A CSV is a plain text table, which is why every program takes one. What is inside it, how to open it safely, and the Excel trap that ruins data.

JPG throws detail away to stay small, PNG keeps everything. Which to use for photos, logos, screenshots and web pages, with the honest trade in each case.

A PDF is a printed page, not a document, which is why editing feels hard. Six free ways to change one, and which to pick for your kind of file.

A 500 means the server tried to build your page and something in its own code stopped it. What a visitor can do, and eight checks for the owner.