In this chapter we present a brief introduction to the subject of radio astronomy, and discuss the motivation for this project. We discuss about the history of radio astronomy, the electromagnetic spectrum, radio emission mechanisms like thermal radio emission, plasma oscillation, spectral line emission and non-thermal or synchrotron emission etc. We also discuss in brief about radio telescopes, measurable quantities by a radio telescope, beam pattern and resolution of a radio telescope, surface brightness (also called as flux density) measured by a radio telescope and emission mechanisms at low radio frequencies. Lastly we present an outline of the thesis.