  I review recent works on the symmetry and the structure of the
superconducting gap in Fe-based superconductors and on the underlying pairing
mechanism in these systems. The experimental data on superconductivity show
very rich behavior, with potentially different symmetry of a superconducting
state for different compositions of the same material. The variety of different
pairing states raised the issue whether the physics of Fe-based superconductors
is model-dependent or is universal, governed by a single underlying pairing
mechanism. I argue that the physics is universal and that all pairing states
obtained so far can be understood within the same universal pairing scenario
and are well described by the effective low-energy model with a small number of
input parameters.
