Gravity is often described as a force in everyday language and classical physics. However, in the context of modern physics and our current understanding of the fundamental forces, gravity is not considered a force in the same way as the other three fundamental forces: electromagnetism, the strong nuclear force, and the weak nuclear force.
In general relativity, which is the modern theory of gravity, gravity is not described as a force but as the curvature of spacetime caused by mass and energy. According to this theory, objects with mass or energy distort the fabric of spacetime, creating a gravitational field. Other objects moving in the vicinity of this curved spacetime follow curved paths, which we perceive as the force of gravity.
Unlike the other fundamental forces, gravity is not mediated by a particle. The other forces are mediated by particles called gauge bosons. For example, the electromagnetic force is mediated by photons. In the case of gravity, a hypothetical particle called the graviton has been proposed as the mediator of the gravitational force, but the existence of gravitons has not been confirmed by experimental evidence.
One key difference between gravity and the other forces is that gravity affects all objects with mass or energy, whereas the other forces have specific charges or properties that determine their interactions. Gravity acts universally on all objects, regardless of their composition or charge.
In summary, while gravity is often colloquially referred to as a force, in modern physics it is not considered a force in the same sense as the other fundamental forces. Instead, gravity is described by general relativity as the curvature of spacetime caused by mass and energy.