Squatting is when a person or people gain access to an unoccupied or abandoned building and start living there  without the owner's permission. In some jurisdictions, if done the right way a squatter may be able to obtain legal ownership of the property if they meet certain requirements such as, living there without hiding it for 5 years, making improvements to the property and paying the taxes on it. But if the owner shows back up on the 364th day of the 4th year and pays the taxes, they'll maintain ownership of their property.