There are only two basic ways to divide the product categories of connectors, namely, according to the shape structure and working frequency. According to the shape and structure, it can be divided into circle and rectangle, and according to the working frequency, it can be divided into low frequency and high frequency. The frequency is divided by 3MHZ. At present, the most commonly used connector is the rectangular connector, whose section is trapezoidal and approximate to rectangular. In addition, it can also be divided into many different types according to other purposes, installation methods, special structures, special performance, etc. Furthermore, according to the universality and relevant technical standards of rectangular connectors, they can be divided into low-frequency circular connectors, rectangular connectors, printed circuit connectors, RF coaxial connectors, optical fiber connectors, etc.

Secondly, the use advantages of the plug-in. The first connector can improve the production process very well. The connector not only simplifies the assembly process of electronic products, but also simplifies the batch production process. Second, it is very convenient for maintenance. For example, if an electronic component fails, the failed component can be replaced quickly when the connector is installed to restore the normal use of the component. The third is that the connector is easy to upgrade, because with the development of technology, the components can be updated when the connector is installed, and the old can be replaced with the new. Fourth, connectors can further improve the flexibility of design, and people have greater flexibility when using connectors to assemble systems.