Atomic-force microscopes (AFMs) and nanoindenters (NIs) both work by probing a surface. AFMs are specially designed for high-resolution imaging, and NIs are specially designed for measuring mechanical properties. However, because AFMs and NIs share some operating principles, their functions have some degree of crossover. The principles of profi lometry and nanoindentation are explained in detail elsewhere [1, 2]. The purpose of this note is to explain the design features that make each type of instrument well suited for its intended function. This note also addresses the pros and cons of using one type of instrument to perform the intended function of the other.