New to Object Oriented programming ? A brief introduction:
Object Oriented programming is a type of programming language where the coding is composed around an actual (real world) object. Where with "linear programming" a program starts, runs through a sequence of routines and ends. Coding in OO means that routines (methods) are build for an object (class).
Especially with more complex programs, setting your coding up in OO poses a strong platform for stable coding. Instead of a big bin of routines, methods belong on their class. Organised by nature. And of course not just methods, also attributes (variables, tables) belong to a class.
Even without visibility of methods and attributes (public, protected and private, encapsulation), static and instance classes, global and local classes, interfaces, inheritance, polymorphism and friends and events: Object Oriented programming is the way to go.
Abap is Object Oriented ? Yes and no: is supports the object oriented concepts, however they can also be ignored. Best of both worlds ? It's a backward compatibility thing, which is no guarantee for proper Abap coding. With Object Oriented programming, the classic Dynpro (screen with processing) is not supported. You will still need a report or function group for this.