The discovery of exoplanets has altered our understanding of the universe. But, for the planets to show the possibility to harbour life in it or have biosignatures, it must have optimum physical, biological, geological and chemical conditions. There are two types of indicators of habitability: direct and indirect. The former indication is the presence of water and its stability on the surface of the planet. Thus, the reflection from the waterbody will lead to ‘glint’. Polarization of light is another alternative method to find water. The reflection, emission of radiation help us to characterize habitable zones. Indirect methods include the presence of CO2 and water vapour in the atmosphere, size of the planet and extent of axial tilt. The presence of magnetic fields and satellites revolving around the planet also play an important role. In this review article, we aim to provide a comprehensive explanation to the researches done till date to characterize habitable zones for exoplanets. The methods devised to retrieve results will also be discussed. Future prospects, the voids which could be amended are also elaborated. This could give cosmological research a new dimension, demonstrating that life is not limited to our planet.