Polariton is a bosonic quasiparticle. When an electromagnetic wave strongly
interacts with the dipole active transition of the medium, then polariton is formed [1]. In other
words, when light scatters and goes through any interrelated resonance, then the polaritons can
be formed. In this chapter, the history of polariton, category of polaritons, their constituents,
and light-matter interaction have been explained. Special condensate behaviour of polaritons
like polariton lasing, superfluidity, and quantized vortices are also explained.
Keywords: Building block of polaritons, History of polaritons, Light-matter coupling, Polariton laser, Superfluidity, Quantized vortices.
