Yes, a website can have many different widgets. You can have different widgets on the same site in different pages/sections or even multiple widgets on the same page. Note that each widget corresponds to a "position" on you site and is designed to fit perfectly onto that specific position in terms of size and structure. For example an article widget should not be implemented in the sidebar since they most probably differ in size and structure.
The most common is to start with an article widget. Then you can expand with as many different variations you want. Some examples on widget types:
- Infeed (between posts)
Read more: How to add multiple widgets on a page