Here's a breakdown:

* Mass: The amount of matter in an object.

* Force of Gravity: The attractive force between any two objects with mass.

Direct Relationship: This means that the two quantities change in the same direction.

* If you increase the mass of an object, the force of gravity it exerts on other objects also increases.

* If you decrease the mass of an object, the force of gravity it exerts also decreases.

Example:

* Imagine a small ball and a large boulder. The boulder has much more mass than the ball.

* The boulder will exert a stronger gravitational pull on other objects (like a nearby small rock) than the ball will.

Formula:

This relationship is expressed mathematically by Newton's Law of Universal Gravitation:

* F = G * (m1 * m2) / r^2

Where:

* F is the force of gravity

* G is the gravitational constant

* m1 and m2 are the masses of the two objects

* r is the distance between the centers of the two objects

This formula shows that the force of gravity is directly proportional to the product of the masses (m1 * m2).