Einstein's theory of gravity

According to Einstein, gravity is not a pulling forced but a curvature in spacetime.

For example:-
       Consider earth, when it occupies a particular place in space it forms a curvature around it like when a boat displays a particular amount of water below it when it floats.
      Or when you sit in a bed, the bed gives way to accommodate you and a little of the area around the bed gives way to accommodate you too.

         So according to Einstein each object in space bends a particular amount of space towards it and bigger the object bigger the space, and black hole have infinte gravity.

             This explains as to why each object rotates around a particular orbit around other objects like when the moon rotates around the earth, earth rotates around the sun.
              This principle has been used to launch satellites in to space.