Facebook is a social networking app, the concept of facebook is very good because it connect the peoples with their friends and relitives.it removes the distance from the peoples.it gives us information about everything that vo neend as like daily affairs etc. its features is very incredible, we give our pictures and video on our timeline which show our picture to other peoples, now in modern age we can make video or audio call on facebook with facebook massenger, if we talk about its usefulness, it give us information any time and connect us to the world. we can get any type of knowledge from facebook pages.