Bosons are a type of subatomic particles which follow Bose Einstein Statistics.The other type is fermions. The word boson was coined by Paul Dirac.
Examples of bosons include:Gluons,Photons,W and Z bosons and Higgs Boson.
Pauli's Exclusion Principle--- Bosons do not follow Pauli's Exclusion Principle.Due to this they can occupy the same quantum state within a quantum system. Eg:Photons produced by a laser.
Since bosons with the same energy can occupy the same space,bosons are force carrying particles,including composite bosons such as mesons.
Since Fermions cannot occupy the same quantum state,they make up matter,while bosons,help in transmission of energy.
Properties of certain Bosons--- Photons:Carry electromagnetic force. Higgs Bosons:Provide mass to the W and Z bosons via the Higgs Mechanism. W and Z boson:Force carriers which mediate the weak force. Gluons:Fundamental force carriers of strong force.
Bose–Einstein statistics encourages identical bosons to crowd into one quantum state, but not any state is necessarily convenient for it. Aside of statistics, bosons can interact – for example, helium-4 atoms are repulsed by intermolecular force on a very close approach, and if one hypothesizes their condensation in a spatially-localized state, then gains from the statistics cannot overcome a prohibitive force potential. A spatially-delocalized state (i.e. with low |ψ(x)|) is preferable: if the number density of the condensate is about the same as in ordinary liquid or solid state, then the repulsive potential for the N-particle condensate in such state can be no higher than for a liquid or a crystalline lattice of the same N particles described without quantum statistics. Thus, Bose–Einstein statistics for a material particle is not a mechanism to bypass physical restrictions on the density of the corresponding substance, and superfluid liquid helium has a density comparable to the density of ordinary liquid matter. Spatially-delocalized states also permit for a low momentum according to the uncertainty principle, hence for low kinetic energy; this is why superfluidity and superconductivity are usually observed in low temperatures.
Photons do not interact with themselves and hence do not experience this difference in states where to crowd.