Corpses begin in a fresh state, but will deteriorate over time.
Corpses can be butchered, buried or burnt depending on need. Those that deteriorate completely will leave distinctive skeletons in their place. They can also be consumed raw, even by humans. Humans that consume corpses without the Cannibal trait will suffer negative thoughts.
Corpses produce negative beauty, and colonists lacking the Bloodlust or Psychopath will suffer negative thoughts on seeing human corpses (with worse debuffs for rotting corpses).
Butchered corpses produce meat and leather.
Butchering a human corpse places a negative "We butchered humanlike" thought over the entire colony, and the butcherer will also suffer a "I butchered humanlike" debuff. Colonists with the Psychopath trait, however, are immune to these.
Corpses can be burnt in an electric crematorium.
A cheaper way of burning corpses is to use weapons that produce fire, such as molotov cocktails or incendiary launchers. These can be manually-targeted at corpses to set them on fire. A walled-off corpse stockpile can dispose of multiple corpses at once.