CareerCup

I would explain it using a school analogy, thats what a 10yr old kid can relate closely.
If you look at the world as a school, then all humans are in a single 'class' and each of us are an 'instance' of this class. All of us have characteristics or 'attributes' such as weight, shape, bodytype etc.. and humans have behaviors or 'methods' such as breathing, walking, thinking etc...
Now, when you look at a person playing baseball, you don't know the details how he is playing, like he/she looks at the ball, thinks something in the mind about how to hit the ball and hits it. This is basically 'encapsulating' details from others.
And as humans we are all animals and there are other animals such as tigers, elephants, monkeys, fish etc... so all tigers are in one class, elephants are in a class and so on. So all the different class of animals are 'inherited' from animal class. All animals have some similar behaviors such as talking, walking, breathing etc... each of the animal types have different forms of these behaviors. For example if a dog want to talk it barks, if a bird wants to talk it chirps and as humans we talk using sounds, so all the animals have different forms for the similar behavior which is 'polymorphism'.
Hope this helps!

Find me a 10yr old who wants to know about OOPS first..

Make it a part of a video game :P

I will only try if I am guaranteed that I will make money weather the 10 year old gets it or not.

you can explain it by comparing Objects to Lego's blocks.

@chennavari ...mcd laundi :P