  Nearly 30 years ago, two-photon interference was observed, marking the
beginning of a new quantum era. Indeed, two-photon interference has no
classical analogue, giving it a distinct advantage for a range of applications.
The peculiarities of quantum physics may now be used to our advantage to
outperform classical computations, securely communicate information, simulate
highly complex physical systems and increase the sensitivity of precise
measurements. This separation from classical to quantum physics has motivated
physicists to study two-particle interference for both fermionic and bosonic
quantum objects. So far, two-particle interference has been observed with
massive particles, among others, such as electrons and atoms, in addition to
plasmons, demonstrating the extent of this effect to larger and more complex
quantum systems. A wide array of novel applications to this quantum effect is
to be expected in the future. This review will thus cover the progress and
applications of two-photon (two-particle) interference over the last three
decades.
