How to make a website like facebook or youtube?

[Tj]

Those websites are incredibly complex and have many different elements and technologies, developed and perfected by tens if not hundreds of developers over several years, working together to produce the information you see and provide the experience you get.

I think what you want to know, is how to make dynamic websites (i.e. websites that can change, and not always show the exact same information). In order to accomplish this, you need to learn some sort of server-side programming language. The most popular for beginners and hobbyists is PHP because it is free, yet very robust.

In order to get started, I would recommend you find a web host that supports PHP sites (there are many) and then do a Google search for "PHP Tutorial". There is an endless amount of information out there on the subject, the trick is finding a good place to start.

Good luck.

P.S. Don't let any of that discourage you! Facebook was originally developed by Mark Zuckerberg who was just a 21 year old psychology student in his dorm room. It really was nothing more than a hobby he did on the side, now he's the head of multi-billion dollar organization. Keep in mind, that version was not what you see today, but it offered the functionality that people wanted. He also built it in PHP.