In this seminar we will take a close look at philosophical work on the nature and explanatory role of theories and models in science. We will tackle questions such as: What are scientific theories? How are they structured? What are scientific models and how do we gain knowledge from them? We will also examine the issue of scientific representation, aiming to shed light on the relationship between theories, models, and what they represent. The seminar is particularly suited to students that have some background in philosophy of science, and/or that have attended introductory courses on the topic.