Physical Description
House-elves are between two to three feet tall, with spindly arms and legs and over-sized heads and eyes. They have pointed, bat-like ears and high, squeaky voices. Rather than conventional clothing, house-elves wear discarded items like pillowcases and tea-towels. Though when they are freed, and when they are able to pay for proper clothing, they seem to not know how to wear it.

Habitat
They serve wizards and witches taking residence in elaborate establishments, like mansions, and must do everything that their masters command unless they are freed. A house-elf can only be freed when their master presents them with clothes.

Magical Abilities
All house-elves have their own brand of powerful magic, which allows them to perform tasks, such as apparating, where wizards and witches cannot.  However, unlike most magical beings, the house-elf is actually quite happy not to own a wand, as almost all house-elves never require one for the type of magic they perform (mostly domestic spells and Apparition). Apart from that, house-elves usually have to obtain permission from their masters before they could use their own brand of magic, as doing so without their consent would be treated as a sign of transgression, leading to the house-elf in question to apply self-inflicted injury upon himself or herself.