An introduction to analytic ontology. Part 1 deals with the question, What is ontology?, focusing on (i) the interplay between ontological and broadly metaphysical concerns, and (ii) the difference between material ontology and formal ontology. Part 2 deals with the question, How is ontology done?, focusing on (i) the delicate interplay between ontology and truth-making (or: between meaning and existence), and (ii) the differences between revolutionary vs. hermeneutic, prescriptive vs. descriptive, and absolute vs. relative approaches to ontology. Part 3 surveys (...) the state of the art in a number of areas, both in material ontology (e.g., the problem of universals, the status of objects and events, the ontology of mathematics, of the physical sciences, of the social sciences) and in formal ontology (identity, ontological dependence, part-whole relations). (shrink)