This lecture focuses on the importance of vertices in optimization, explaining how to identify them in a polyhedron by looking at convex combinations of feasible points. The instructor presents a theorem stating that a polyhedron in standard form contains at least one vertex. The process of finding vertices involves activating constraints and using linear algebra to ensure feasibility. By setting non-basic variables to zero and checking the basic variables' positivity, one can efficiently determine the vertices of the constraint polyhedron, a crucial concept in optimization.