Abstract: In this talk, we will give a friendly overview of Deligne’s mixed Hodge theory on the cohomology of quasi-projective varieties. We start by reviewing pure Hodge structures and motivate the necessity of mixed Hodge structures with very simple examples. We then define mixed Hodge structures formally and show how the logarithmic de Rham complex enters into this picture. Lastly, we mention briefly applications of mixed Hodge theory.