Differentiation allows us to find the rate of change of one variable with respect to another. Calculus helped improve navigation by providing a better understanding of how celestial bodies move. Differentiation and integration can help solve real-world problems like determining maximum/minimum values, finding tangents and normals, solving equations using Newton's method, optimizing costs/profits, and determining radii of curvature. The presentation concludes with information on increasing/decreasing functions and the nature of stationary points.