In addition to the differences in function, installation environment, internal structure, and controlled objects, distribution cabinet and switchgears are characterized by different external dimensions. The power distribution cabinet is small in size and can be hidden in the wall or standing on the ground. The switchgear is bulky, and it is only installed in the substation and power distribution room. Switchgear is a kind of electrical equipment. The outside line of the switch cabinet first enters the main control switch in the cabinet, and then enters the sub-control switch, and each branch is set according to its needs，such as instruments, automatic control, motor magnetic switches, various AC contactors, etc. Some are also equipped with high-voltage room and low-voltage room switchgear, with high-voltage busbars, such as power plants, etc. And some are also equipped with low-cycle load shedding to protect main equipment. The main function of the switchgear is to open and close, control and protect the electrical equipment in the process of power generation, transmission, distribution and power conversion in the power system. The components in the switch cabinet are mainly composed of circuit breakers, disconnect switches (insolator switch), load switches, operating mechanisms, transformers and various protection devices. There are many classification methods of switchgear, such as the installation of circuit breakers can be divided into removable switchgear and fixed switchgear. Or according to the structure of the cabinet, it can be divided into open switchgear, metal-enclosed switchgear, and metal-enclosed armored switchgear. According to different voltage levels, it can be divided into high-voltage switchgear, medium-voltage switchgear and low-voltage switchgear. Mainly used in power plants, substations, petrochemicals, metallurgical steel rolling, light industry and textiles, factories and mines, residential quarters, high-rise buildings and other different occasions. Power distribution cabinets (boxes) are divided into power distribution cabinets (boxes), lighting distribution cabinets (boxes), and metering cabinets (boxes), which are the final equipment of the power distribution system. Power distribution cabinet is a general term for motor control center. Power distribution cabinets are used in situations where the load is relatively scattered and there are few circuits. In the motor control center, the power distribution cabinet is used for the occasions where the load is concentrated and there are many circuits. They distribute the electrical energy of a certain circuit of the upper-level power distribution equipment to the nearest load. This level of equipment should provide protection, monitoring and control of the load.