This document discusses topology optimization. It begins by defining topology and optimization separately, then explains that topology optimization is a mathematical approach that optimizes material layout within a design space to meet performance targets while minimizing a given objective like mass or deflection. It provides an example of using topology optimization on a cantilever beam by dividing it into elements, removing less stressed elements through iterations, analyzing the results, and continuing until the objective is met. Finally, it mentions software tools used in the topology optimization process and some applications.