HOW DOES GRAVITY DO WHAT IT DOES WHILE HOLDING THINGS TOGETHER?

HOW DOES GRAVITY DO WHAT IT DOES WHILE HOLDING THINGS TOGETHER?

GRAVITY INTERACTS WITH MILLIONS OF BODIES THAT ARE MOVING THROUGH SPACE. IT AFFECTS AN ENTIRE GALAXY.  HOW? AS GALAXIES MOVE THROUGH SPACE, ALL MATTER WITHIN THE GALAXY IS AFFECTED BY ONE ANOTHER. Law of universal gravitation:  A law stating that any two masses...