House-sitting is when you live in a person's home while they are on vacation. They want someone to live in their house because they are nervous about leaving it empty. They may have a pet(s) that need to be fed. They may have plants that need to be watered. They will want their mail brought in. Most will let you go to work or school during the day as long as you spend evenings and weekends in their home. Pay varies, depending on the people. It is not difficult but you are responsible for taking care of their home.