Why REST API need method name important?

I REST full API has some method name like (GET, PUT, POST etc.) for some specific operation (CRUD) But I can perform any operation using any of the methods

Example: 1. I can create or insert a new document or delete or update using GET method. 2. I can post or update or delete using POST method

So, Why need this method to specify when we call any rest full API?

via Anupan