An autopsy is a specialized surgical process/procedure during which a physician performs a thorough examination of a corpse to determine the cause and manner of death, and determine what disease processes and injuries were present at the time of death. Typically the physicians that perform these procedures are pathologists
. They can be performed for medical or medical-legal reasons. Autopsies can be thought of in 2 main categories, external examination (when that is all that is needed), and internal examination (the surgical dissection that most people think of with regards to autopsy).
Forensic biopsies are those that are performed in relation to a criminal case to help determine the cause of death, and in so perhaps give some information about the perpetrator. In medical cases where the cause of death is known, and there are no questions about the pathophysiology, an autopsy is not typically performed. So speaking in very general terms, if someone were to die of a stroke, and there were no other obvious uncertainties about the cause of death, an autopsy is not typically performed. I hope that this helps. Without having more information about the situation leading up and surrounding the death, it is hard to answer the question completely.