Hence you look at the code as a big pile of different procedures that are coupled with each other, one calling the other, or one calling many while some not calling anything but rather doing specific computations and returning the results.
Event Driven?! I do not believe there is such a method that stands alone, Event driven is a charactaristic rather than a development approach.
Object Oriented Programming (OOP) looks at your problem ad breaks it down to different objects, each object has consists of a number of elements, called Members and Methods. (i.e variables and functions respectively)
so your problem is then defined as the different objects working together and inside each other sometimes in a closely coupled manner.
the conclusion is, OOP deals with objects and operations on those objects, where as procedural development breaks down computation to little pieces.