One player can own only one house at the time. Owning a house means that you have to pay taxes or you will risk losing your house. You can also teleport to your house with the House Recall skill which is under the General Skills in the skills menu.
Depending on the house size your friend(s) can bind to it as well. There are various useful house addon items which can be placed in your house, there are both usable and only decorative house addons.
A house can be either bought from other a player or build, both require quite a lot of resources. The house plots are predefined in the world and most of them are in villages, but there are some here and there around the world, waiting to be found.You can manage your house via the Journal.