State Newton’s law of gravitation. Hence define G. What are the units and dimensions of G? Why is G called a universal gravitational constant?

In 1687, Newton published the universal law of gravitation in his book Principia. The law states: Every particle in the universe attracts every other particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This force acts along the line joining the two particles.

Consider two bodies with masses m ₁ and m₂ separated by a distance r.
According to the law:
F ∝ m ₁ m₂ and F ∝ 1/r²
F ∝ m ₁m₂ /r²
or F = 𝐺 m ₁ m₂ / r²
where 𝐺 is the universal gravitational constant.
Definition of 𝐺 :
If m ₁ = m₂ = 1 and r = 1, then F = G. The universal gravitational constant is defined as the force of attraction between two bodies, each of unit mass, placed 1 unit distance apart.
Units of 𝐺 :
SI Unit: 𝐺 = 6.67 x 10⁻¹¹ Nm² kg⁻²
Cgs Unit, 𝐺 = 6.67 x 10⁸ dyn cm²g⁻².
Dimensions of 𝐺 :
From the formula 𝐺 = F r² / m ₁ m₂ , the dimensions of 𝐺 are:
[G] = MLT⁻² x L² / M x M = [M⁻¹ L³T⁻²]
Properties of 𝐺 :
The value of 𝐺 is constant and does not depend on the nature, size, or composition of the interacting bodies, making it a universal constant.