Perhaps to research the differences between Object Orientated Programming and Procedural programming. The first is event driven and the second is procedural.
With an event driven environement you can slot in code that allows sub code to respond to events. Windows is an eevent driven environement and slots in programs that you launch that have other programs that respond to events from keyboard and mouse events.
Procedural is very much like th eprograms that are used to get your pc up and running when you tuen it on, they just follow a sequence without any event interuptions and will stop when the list of instructions have been completed.
hope thats helps also?