How the Internet works

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Read Mozilla’s great introduction to how the Internet works.

Also, check out this animated guide to how the internet works.

Internet basics

Ajax requests

Ajax is a way of making a request to get resources with JavaScript, without reloading or refreshing or redirecting the page. Meaning, it can happen in the background, then update a specific part of the page. This is the concept behind web applications, where interaction with a page–clicking or selecting things, etc–doesn’t force your page to reload, but merely updates that particular part of it.

Web frameworks

Understanding Caches and Caching

Let’s say I have a computer and I request to view the website “”. The server returns to me several files: an HTML index file, a stylesheet, and several images that the HTML file needs.

Now, let’s say that tomorrow, I ask again for these files by making a request to load “”. In the interim, no changes have been made on the server to those files. So, in order to conserve time and not re-request files that are unchanged, my computer simply re-loads the files it already received for this website, after checking that those files aren’t supposed to be expired.

This process of not re-requesting files is called cacheing, and most modern browsers do this. It’s an effective way of speeding up the loading of a website, but there immediately arises a need to manipulate these caches, for a variety of reasons.

Registering your domain and understanding DNS