House-elves are small humanoid creatures who inhabit large houses belonging to wealthy Wizarding families. They are “bound” to the family of the house, which means they do all manner of menial tasks for them until they die. House-elves are apparently very happy with this arrangement and consider it a matter of pride that they serve faithfully and do not betray their families.
A house-elf is a short creature with large bat-like ears and enormous eyes. It is difficult for an inexperienced human to tell the difference between male and female house-elves, although the females generally have higher, squeakier voices. Neither male nor female house-elves wear clothing (and they would consider it shameful to do so); instead, they cover themselves in towels, tea cozies, or pillowcases. If their owner gives them an article of clothing, it breaks the “enslavement” and the house-elf is free. For most house-elves, this would be the ultimate insult and they would be shamed forever.www.hp-lexicon.org