I know we have have hearing, learning and reading so many things about OO and procedural code from the day we are onto the world of OO. But I just figured out one nice point differentiating between them found in the book Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin aka Uncle Bob.

Procedural code (code using data structures) makes it easy to add new features without changing the existing data structures. OO code, on the other hand, makes it easy to add new classes without changing existing features.

I think above single statement is more than enough if one wants to know the real difference between OO and procedural code. And again you gotta to have some OO experience in order to understand the depth of the statement.

So far, I have been satisfied with the book (completed around 10 chapters) and if you are interested in making your code clean (in the sense of usability and design), then I strongly recommend the book.