What are Hooks and How are they used? Went thorough the explanation on the topic but can't wrap my head around it

Question

So in the ERC720 contract there is a _transfer function which is calling a hook named _beforeTokenTransfer().

As we see in the image _beforeTokenTransfer is called and I understand it may be calling the function to check something before doing the transfer. That's fine but when i navigate to the _beforeTokenTransfer function it has no logic inside it. It just accepts the same arguments _transfer accepts then what is the use of adding it?

As I described before, let me show you the _beforeTokenTransfer function as well.

As you see in this pic, there is no logic inside the function, I was thinking that hooks are used because it is going to add some extra functionality to the current function like checking some conditions before deploying. But this function is just accepting the same argument?

Please can someone explain me this?

Answer 1

Basically, it is a function for you to override; You can insert some checks here before the main execution code.

Or simply leave it as it is, it won't cost gas.

To read more about hook:

https://docs.openzeppelin.com/contracts/3.x/extending-contracts#using-hooks