Portrait

These works are subset of what you see in Figurative art. The difference obviously is that these works focus on an individual and typically will focus on the face. The artist is trying to understand all the different relationships that go into a particular person's energy and features. The different ways a face or head can be painted allow the artist to show something more about a subject than what you get with a photographic portrait.

Still Life

These works are a subset of what you see in Interior.  The difference is they focus on a smaller space.  For example they may focus on studying the relationships and colors and shapes of a few articles on a table.  The important thing here is not necessarily the objects but the way the artist is able to convey a feeling of space and spaces between objects.  Of course this is happening in all art work, but here it's focused on a microcosm and that allows the artist to work on something that is not changing and so he or she can penetrate more deeply into the relationships.