  Collapse models represent one of the possible solutions to the measurement
problem. These models modify the Schr\"odinger dynamics with non-linear and
stochastic terms, which guarantee the localization in space of the wave
function avoiding macroscopic superpositions, like that described in the
Schr\"odinger's cat paradox. The Ghirardi-Rimini-Weber (GRW) and the Continuous
Spontaneous Localization (CSL) models are the most studied among the collapse
models. Here, we briefly summarize the main features of these models and the
advances in their experimental investigation.
