To meet the energy demands of the growing population, shift towards renewable sources of energy is the need of the hour. The wastes generated in the households and farms can be efficiently treated by biomethanisation technology. In the biogas digester, the organic wastes undergo anaerobic degradation in the presence of different groups of micro-organisms to produce a mixture of gas with higher amounts of methane. To efficiently use the produced biogas for various purposes, it is necessary to upgrade the biogas to biomethane. This review includes, the biochemical processes involved in the biogas production along with the parameters affecting the operations and also the various methods involved in upgrading it.