What exactly is svabhava?
Svabhāva stands for inherent existence.

From an early Madhyamika viewpoint, there are two types of dependent-arising:


Causal dependence
Dependence on parts


While impermanent phenomena depend on both causes and parts, permanent phenomena do not depend on causes and conditions but they do depend on parts. For instance, a chair is impermanent and depends on causes (if it is made of wood, wood is a substantial cause, etc) and depends on its parts (the legs, etc). Permanent phenomena such as space, emptiness, cessations, etc. depend on parts. For instance, emptiness is emptiness of something on which it depends (not causally, but in terms of part). Therefore, even emptiness, a permanent phenomena, is empty of inherent existence because it is a dependent-arising.

From a Madhyamika-Prasangika viewpoint, there are two types of dependent-arising. The third level is the most subtle:


Dependence on name.


We say that the meaning of something being empty of svabhāva is that, if you look for it with a mind analyzing the ultimate, you will not find it. Now, if you ask yourself "is the chair its legs... is it the material it's made of... etc" you will find that the chair is merely labeled upon these without being any of these. We say that it is "merely labeled".


This presentation is incomplete and cartoonish because there are various Madhyamika [sub]schools, some for which inherent existence and true existence are synonymous, some not.