The study of physical phenomena basic to electronics, such as discharges, thermionic and field emission, and conduction in semiconductors and metals. Physical Electronics deals with the actual phenomenon occurring within the device during its operation. However, in the part of electronics, we study how an electronic device actually works. On the other hand, electronic engineering is the application part of core electronics and under this section, we deal with successive development. Finally electronics can be defined as "the field of science and engineering which deals with electronic devices and its utilization". The study of physical phenomena basic to electronics, such as discharges, thermionic and field emission, and conduction in semiconductors and metals.