Which website type should I use? [on hold]

I am a wordpress user for more than two years, I've seen many good things like getting an awesome theme and install it, find cool plugins, it's very friendly when posting things, but there are lots of limits, and can only be solved by having a very expensive wordpress hosting.

I need to know clearly what kind of website to choose to have a limitless website with register options, posting, sharing, dayly Traffic...

For example:

1. stackoverflow


2. wikihow


3. videoCopilot


4. deviantart


5. https://mattrunks.com/


6. vimeo


7. mashable

I am sure that most of them don't use wordpress, the question is what kind of website programming language do they use?, HTML, Javascript, python, PHP...? which web hosting they have? I don't ask for copying the websites i just need an explanation, procedure or technique of making one site which shares the same characteristics.