While the natural sciences are concerned with this or that kind of objects, philosophers are often concerned with the nature of "reality" or "being" in general.
When we ask questions about what is real or the nature of reality in general, we are asking metaphysical questions.
When philosophers construct theories of reality they are engaged in metaphysics.
Some examples of metaphysical questions include the following:Metaphysical questions are also sometimes subdivided into:
What sorts of things are real vs. mere appearances? Are there material objects? Are there mathematical objects? Are the immaterial souls? What sorts of relations do real things bear to each other? What do we mean when we say something is "real"? What is the origin and structure of the things that are real? Ontological questions: What does it mean for a thing to "be" or to "exist"? Such questions are often said to be about "Being" in general. Cosmological questions: What is the origin and structure of the sorts of things which do have being, which are "real"? How is the "universe" or "Reality" constructed?