A maid is a female person employed in domestic service for the maintenance of one's home.
Maids typically are in charge of the domestic chores like cooking, washing, cleaning, among other things. It is also fairly common for maids to take on the role of a nurse in taking care of the elders and people with disabilities. Maids are often required by their employers to wear a distinctive uniform.
Wealthy families typically employ one maid to take care of the house and work full day. It is a hard and tiring work, and they are looked down by others due to their position as servants. Nobles, Lords or Royal families that own castles tend to have a whole team of maids, since it requires a far more extensive work. Maids with a skill level tend to be more profficient at the task and sometimes even become Head-maids that lead and judge the other maids' work.
Butlers are the male version of the maid, although they are typically more respected and in a higher position than the female maids.