How the web works

Before writing any code, know what you are building into. This takes five minutes and saves a great deal of confusion later.

You type bvlogic.academy and press enter. Then:

1. The name is looked up. Computers do not use names, they use numbers. DNS turns bvlogic.academy into an address like 109.106.244.188. This is why a new website is not visible everywhere immediately — that lookup information takes time to spread.

2. Your browser asks that address for the page. A request goes out. The machine that answers is a server — an ordinary computer whose job is waiting to be asked for things.

3. The server responds with a file: HTML, and usually instructions for the extra files it needs.

4. Your browser builds the page, fetching the CSS, images and JavaScript the HTML refers to, and drawing the result.

That is it. The whole web is requests and responses.

Two distinctions worth having now.

Front-end and back-end. Front-end is what runs in your browser — HTML, CSS, JavaScript. Back-end is what runs on the server before the answer is sent — checking a password, reading a database. A rough test: if a visitor could see it by viewing the page source, it is front-end. If it must stay secret, it belongs on the back-end.

Static and dynamic. A static page is a file, the same for everyone. A dynamic page is assembled per request — your name at the top, your fees, your attendance. Static is faster, cheaper and safer; dynamic is necessary when the content depends on who is asking.

This course builds a static page. That is not a lesser thing — an enormous number of real, paid websites are exactly that.