House-elves, commonly referred to as simply elves, are magical creatures that are immensely devoted and loyal to the one designated as their master. House-elves are typically found under the employment of schools, old wizarding families and other establishments. Despite popular belief, house-elves love serving others and are only happy when bonded to a family. Despite their short stature, elves are exceptionally powerful magic-wielders and have their own brand of magic that doesn't require a wand, but it is not totally unknown for elves to possess one.
The origins of the elven race or even when they fostered their desire to serve are lost to history, but the earliest cases of house-elf servitude under wizards date back to the days of the Roman Empire, where several emperors kept house-elf servants. House-elves are quite long-lived, with their life expectancy being around 200, and in addition to being fantastic home-carers and cooks, are excellent wine-makers; elven wine is some of the most coveted beverages in the entire wizarding world.
House-elves breed infrequently and never without their master's permission. House-elves do take a mate, although once again, never without their master's permission. These requests are hardly ever denied; wizards have a vested interest in the procreation of their servants, as it means more elves to help around the house.