Schiff bases, which were first obtained by the German chemist H. Schiff in 1864, are used in the paint industry, polymer technology, pharmaceutical industry, medicine, agriculture, preparation of rocket fuel, and explanation of biological events, and in many other areas due to the groups in their structures. This chapter will be a guide that contains a summary of general information that should be known about these compounds, which have a wide range of use in our daily life. In this chapter, the following topics are planned to be explained. (1) Schiff bases, physical and chemical properties, (2) the formation mechanism of Schiff bases, (3) Schiff base reactions, (4) metal complexes of Schiff base, (5) classification of Schiff bases, (6) biological activity of Schiff bases, and (7) usage of Schiff bases.