Usually this results in either the annihilation of the defending force, or in rare cases, the retreat of the attacking force, depending on the circumstances (example: Out of supplies, or have received heavy casualties).
Whilst in a last stand, the defending force has an opportunity to surrender, but that could also lead to their deaths. This however is really a moral question on if they should surrender or not, because the defending force really has nowhere else to retreat to should they be defeated. Mostly, the concept of a last stand is to ultimately 'go down fighting'.
Battle of the Alamo
Battle of Port Hudson
Battle of Hill 3234
Battle of Long Tan
5 examples of a last stand
Last Stand gives the the warrior 30% of his max health for 20 seconds. As soon as the timer is up, the health gained from last stand is lost. It is a mandatory ability for any protection warrior, whether he or she decides to pvp or pve.