  A short, and definitely not a complete representation of \eta production
processes on hadrons is given. First of all, the different ways of obtaining
the \pi N \to \eta N and \pi N \to \eta N amplitudes are presented. After that,
an overview of results obtained using these amplitudes as input for calculating
processes like: NN \to \eta NN, pd \to \eta ^{3}He, \pi d \to \eta NN and \eta
d, \eta ^{3}He and \eta ^{4}He as well as \eta-light nuclei bond states, will
be given. The experimental and theoretical results will be reviewed. The opened
problems and the way how to solve them will be presented.
