What is the gravitational force between the earth and a body called?

Prove that if a body is thrown vertically upwards,then the time of ascent is equal to the time of descent.

The force of attraction between two unit point masses separated by a unit distance is called

The weight of an object at the centre of the earth of radius $R$ is

$(a)$ Differentiate between $G$ and $g$.
$(b)$ Is the value of $g$ the same everywhere on Earth? Reason out.
$(c)$ How does the gravitational force between two objects change if the distance between them is tripled?

Define the "universal law of gravitation".