  What is the major difference between large and small systems? At small
length-scales the dynamics is dominated by fluctuations, whereas at large
scales fluctuations are irrelevant. Therefore, any thermodynamically consistent
description of quantum systems necessitates a thorough understanding of the
nature and consequences of fluctuations. In this chapter, we outline two
closely related fields of research that are commonly considered separately --
fluctuation forces and fluctuation theorems. Focusing on the main gist of these
exciting and vivid fields of modern research, we seek to provide a instructive
entry point for both communities of researchers interested in learning about
the other.
