Gravity is the result of a mass warping the structure of spacetime, but it's hard to imagine how the structure of spacetime being altered.
I think it helps in addition to the 2D curving sheet illustration by imagining 3D space with "liquid-density." In an empty system, the space liquid-density is uniform and an object with certain inertia just moves straight ahead. When another object B is placed near object A, object B's mass alters the space-density near it to be thinner. Object A moving pass object B will slip toward B because the space near it is thinner. The closer A to B, the thinner space gets and the faster it slips. There is no force involved. It's just objects slipping toward the thinnest density region. The "thinning" of space is mass warping spacetime, which is what we called gravity.
That analogy only seems to work in a system where everything is moving. If two objects are at rest relative to each other they are still attracting each other right?
I think it helps in addition to the 2D curving sheet illustration by imagining 3D space with "liquid-density." In an empty system, the space liquid-density is uniform and an object with certain inertia just moves straight ahead. When another object B is placed near object A, object B's mass alters the space-density near it to be thinner. Object A moving pass object B will slip toward B because the space near it is thinner. The closer A to B, the thinner space gets and the faster it slips. There is no force involved. It's just objects slipping toward the thinnest density region. The "thinning" of space is mass warping spacetime, which is what we called gravity.