Question: We know through [General Relativity](http://en.wikipedia.org/wiki/General_relativity) (GR) that matter curves spacetime (ST) like a "ball curves a trampoline" but then how energy curves spacetime? Is it just like matter curvature of ST?

Answer: 
Matter curves the spacetime because (experimentally verified and mathematically natural) Einstein's equations that govern the spacetime curvature say that the local-curvature-encoding Einstein tensor $G\_{\mu\nu}$ is proportional to the stress-energy $T\_{\mu\nu}$. The latter contains numbers, especially the density of mass-energy and momentum and their flux (which also depends on the local pressure).

Because matter carries mass-energy, it makes spacetime warp. Any other form of mass-energy will do the same thing. I say mass-energy because in the context of relativity, mass and energy are really the same thing due to the well-known formula of special relativity, $E=mc^2$, which says that one unit (e.g. kilogram) of (relativistic) mass is equivalent to $c^2$ units (joules) of energy. 

Mass or energy may be stored in various forms but they ultimately have the very same impact on the spacetime curvature (and other things). Some of the forms of mass-energy look more like mass, other looks like what we used to call energy but there's only one type of quantity that curves the spacetime and one quantity that is conserved.
The source of gravity in GR is not just mass, but the full energy-momentum tensor; this tensorial quantity is a measure of energy, momentum and stress, and applies to ALL forms of matter and all fields that are non-gravitational. Furthermore, there exists a quantity in differential geometry which is automatically conserved in a small neighbourhood on a differentiable manifold, called the Cartan moment of rotation - it turns out that this is mathematically just the dual of the Einstein tensor, and what GR does is relate these two tensorial quantities. This is what the field equations tell us - that the geometry of space-time is related to its energy-momentum content.