What are frameworks? And how do you write them?

I know there is probably a lot of documentation on what a framework is which I will be reading up on, but how exactly do you write a framework for a game. Do you create Module Scripts? How exactly is this all done?

A framework to me is essentially functions that are universally efficient and needed in most games.To make a framework usually you use Module Scripts due to the fact that it can be fired from server and client sided scripts. An example of a framework function that I use is a weld function that only needs 2 variables which are both parts because it welds them the exact distance and position apart then copies down all data into a value model that i can then in turn see. This makes making the game more easier and efficient.

A framework enforces consistency.

The more common frameworks are a bunch of pre-made functions packed together and used within game creation.