Gravitational force is the type of force that exists between any two objects with mass. It is a force of attraction between two objects that is directly proportional to the mass of each object and inversely proportional to the square of the distance between them.

The equation for gravitational force is:

$$F = Gm_1m_2/r^2$$

Where:

* F is the gravitational force in newtons (N)

* G is the gravitational constant (6.674 × 10^-11 N·m²/kg²)

* m1 and m2 are the masses of the two objects in kilograms (kg)

* r is the distance between the two objects in meters (m)

The gravitational force is always attractive, meaning that it always pulls objects towards each other. The greater the mass of an object, the greater its gravitational force. The closer two objects are to each other, the stronger the gravitational force between them.

The gravitational force is responsible for holding the planets in orbit around the sun, the moon in orbit around the Earth, and galaxies together. It is also responsible for the tides on Earth.