An in-law suite is basically a secondary apartment attached or close to your home. To be considered a true in-law suite, this space should include a kitchen, bathroom, and bedroom, as well as a living room or something similar. It should also have its own entrance. These are just some of the necessities every in-law suite should have.
This space allows for whoever is in this space to have privacy but still be in close proximity to the house and family. An in-law suite can be a finished basement, a space over your garage, or even a guest house close by.