What is newtons law of universal gravitation? what do the variables mean?

What is Newtons law of iniversal gravitation:
 that any two masses must attract ech other with a force equal to a constan (gravitation), then muliplied by the product of the two masses and then divided by the square distance between them.
What do the variables mean:
 E*grav: represents the force of gravity between two objects
Cₓ: means "proportianal to"
m₁: represents the mass of object 1
m₂: represents the mass of object 2
d: represent the distance separating the objects ' centers
        
   
                       HOPE I HELPED