Explore the foundations of cosmic inflation in this comprehensive lecture from the Physics of the Early Universe program. Delve into the basics of inflation, the Friedmann-Robertson-Walker (FRW) model, and the composition of the cosmic cocktail. Examine the horizon problem and how inflation provides a solution. Investigate symmetry breaking, vacuum energy, and scalar fields in the context of early universe physics. Learn about the slow-roll approximation and participate in a Q&A session to deepen your understanding of inflationary cosmology.