In Wikipedia, the definition of Object-oriented programming is showed below.
"Object-oriented programming (OOP) is a programming paradigm that represents concepts as "objects" that have data fields (attributes that describe the object) and associated procedures known as methods. Objects, which are usually instances of classes, are used to interact with one another to design applications and computer programs.[1][2] C++,Objective-C, Smalltalk, Java, C#, Perl, Python, Ruby and PHP are examples of object-oriented programming languages."
It has a series of basic theories, like class, subclass, method and so on.
Just as we learnt in Python, a class is defined as "an extensible template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions, methods)".
For example, we defined two classes as Toy and Dog in the exercise we did before. We made 'Bob = Toy()', then Bob belongs to the class 'Toy', it has the implementation of behaviour 'play',which means it can be 'play'ed.In the example above, we can also define other two things as object and method. 'Bob' is one of the Toy, it has its own properties, by which I mean, it is unique over the world, and we call it 'Object'. Maybe 'Bob' have many common properties with other 'Toys', but it is itself. Different from the abstract 'class', it is a specific concept. Just like 'class' is a set of all things around the world containing some things which have similar properties, but 'object' is the particular element in the class. As for the 'method', it defines many things that 'objects' in 'class' can do(but not have to). Let's back to the example above, all 'toys' have the 'method' play, if we make 'Bob.play()', it will return 'Squeak!\n'.
These are the basic definitions in the OOP.
I think it is a very convenient way to create a new class, for dealing with problems more specifically and easily.
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