Both tennis and table tennis have long history and share some similarities, but naturally the details of them are different. Let me explain three different points between tennis and table tennis. The points of view are racket, court and the way how to count the point.
Of course you know, we use a racket when we play tennis or table tennis. However, the racket for tennis is a little big while the racket for table tennis is small.
The court is also distinctive; tennis has much bigger court than its counterpart. We play tennis only outside such as the grass or clay court while we play table tennis only inside, on a ping-pong table.
We should take care of the way how to count the point also. As I have told, both tennis and table tennis have difference, it is not big deal. The most important thing is that everyone loves those sports all over the world.