Well, at sufficiently low energies and sufficiently large length scales we can say gravity is how space time curves under the influence of energy (principly from gravitational mass; another mystery, why gravitational and inertial masses proportional to each other). This picture is called general relativity and it works very well in a wide range of regimes (from motion of planets and galaxies to merger of black holes). However, there should be an exchange of force carrier description (quantums of graviton) at small enough scales or very large energy densities where we fail to make the math work (because we expect certain properties/symmetries from gravitons).

So the word "understand" is a bit loaded. GR is a certain understanding of how gravity works, but it is not a "quantum mechanical" understanding.