Events - Are the one which are performed by the user. 

Example: Assume we have "submit" button on portal. The moment user clicks on submit button, the automation should trigger. Here, we use "click" as event to execute the further process.

Methods -  Methods will be executed by Robots. It's kind of instruction to robot, to perform/wait for some action. 

Example: "PerformClick" is a method, used to perform click operation by robot.

Please correct me if my understanding went wrong.

Thanks!

There is no different definition for either of these terms as they relate to Pega Robotics than what they mean in programming in general. A method is simply something that you can tell an object to so (like a function). An event is that object telling you it has done something Z(or is doing something in the case of synchronous events).