Question

what is universal force of gravitation?
why it is important?

Answer 1

Newton's law of universal gravitation states that every particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
The most important part about this is not only that objects pull on each other, but that two objects attract each other with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. This is known as Newton's law of universal gravitation.