The phrase death certificate can describe either a document issued by a medical practitioner certifying the deceased state of a person or popularly to a document issued by a person such as a registrar of vital statistics

Vital statistics

Vital statistics are the information maintained by a government, recording the birth and death of individuals within that government's jurisdiction. These data are used by public health programs to evaluate how effective their programs are...

 that declares the date, location and cause

Cause of Death

Cause of Death is a 1990 album by American death metal band Obituary. Cause of Death is considered a classic album in the history of death metal. The artwork was done by artist Michael Whelan...

 of a person's death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

 as later entered in an official register of deaths.
Each governmental jurisdiction prescribes the form of the document for use in its preview and the procedures necessary to legally produce it.