Cadmium sulfide (CdS) is prepared with an easy and cost-effective method like the chemical route method. In the preparation method, there are 6-different types of CdS nanoparticles prepared using the capping agent. In this paper, while discussing the optical and electronic properties of cadmium sulfide (CdS), more emphasis has been laid on why you can use it over solar cells and photodetectors. Based on UV¿visible spectroscopy band gaps for 6-different CdS types are measured, which shows that as the size of the CdS particle increases, their band gap increases. The nano size of 6 different CdS particles has been studied through the images obtained from the transmission electron microscope (TEM). CdS are classified as a semiconductor, so the electronic and electrical properties of CdS are also taken care of. In electronic properties, the electrical conductivity, resistivity, electron concentration, and collision times of CdS are calculated based on the data obtained from standard I (current)-V (voltage)-characteristics and bode plots. Based on the optical and electronic properties, the first three CdS types (CdS type-a, type-b, and type-c) are the best semiconductors compared to the rest of the CdS types. Therefore, these three CdS types can be used for the applications of solar cells and photodetectors.