Polarized neutrons have enormous scientific and technological potential in fundamental physics, solid state physics, materials science, biology, engineering applications, etc. Polarized neutrons are most commonly used to investigate magnetic properties of materials, but they can also be utilized for studies of soft matter, biology, and life science. Imaging of magnetic fields can be possible with polarized neutrons. Fundamental symmetries of the universe can be explored as well. Not to forget the spin echo. Some of the techniques to produce spin-polarized neutrons, namely polarizing crystals, polarizing supermirrors, and neutron spin filters, are briefly described.