Rob has a process in his Mac called "User Event Agent" and he doesn't know what that is. Is it necessary? Leo says it is. It just monitors all of his activity. This includes mouse key presses, typing, etc. If he were to stop it, his computer would become unresponsive. He shouldn't really get caught up with what he finds in the Task Manager, especially when the processor and RAM are being used.
Rob's Mac is old, from 2012, and so getting a new MacBook Air is a good idea. Leo's been using the new one for a week, and he says it's simply a better computer. The processor is fast enough, the Liquid Retina display is really nice, and it's light. He can even use the Apple Migration Assistant to move everything over.