  Free-floating planets (FFPs) are the lightest products of star formation and
they carry important information on the initial conditions of the environment
in which they were formed. They were first discovered in the 2000s but still
few of them have been identified and confirmed due to observational challenges.
This is a review of the last advances in the detection of these objects and the
understanding of their origin. Several studies indicate that the observed
fraction of FFPs outnumbers the prediction of turbulent fragmentation and
suggest that many were formed in planetary systems that were later abandoned.
The JWST will certainly constitute a new step further in the detection and
characterisation of FFPs. To interpret these new observations, precise ages for
the nearby star-forming regions in which they were formed will be necessary.
