A method is broadly defined as a procedure that allows you automate a series of steps. The ideal purpose of a method is code reuse, because it allows you to simplify doing something repeatedly.
The process of creating a method in Construct 2 is broken down into events and actions. Actions allow you to specify when a method will be called, whereas events allow you to determine what happens after this condition is triggered.
There are tons of methods that can be created in Construct 2, so there really is a limitless possibility of what you can come up with.
Hope this tutorial helps! Have a great day!