ABSTRACT: In this blackboard talk I review the basic aspects of cosmic inflation and how it addresses the problems of the Big-Bang model. As an introduction, I present the quantities and equations that describe the evolution of the universe, and emphasize certain puzzles that follow from these equations. Next, I explain how a stage of cosmic accelerated expansion (inflation) can explain many of these puzzles, like the smallness of spatial curvature or the homogeneity of the visible cosmos on large enough scales. Finally, I turn to the origin of the structures in the universe (galaxies, clusters, etc.) and how inflation is arguably singled out as the only way to casually explain their origin. Along the way, I try to emphasize what is known vs. what is unknown, what is certain vs. what's uncertain, and what's behind some implicit assumptions about the workings of inflation.