This lecture covers the Two Gendarmes Theorem, which states that if two functions f(x) and g(x) approach the same limit as x approaches a certain value, and a third function h(x) is bounded by f(x) and g(x), then h(x) also approaches the same limit. Important examples involving trigonometric functions are discussed, along with changing variables in limits and dealing with indeterminate forms. The lecture also explores limits as functions approach infinity, defining limits when functions are bounded, and handling indeterminate forms in calculus.