The role of the connecting machine jack is mainly in several ways：

1.Power Connection:A socket is usually used to connect a power source and provide the necessary electrical energy to the device.

2.Signalling:Some sockets can transmit audio, video, or data signals, enabling devices to communicate and exchange information.

3.Peripheral Connection:The socket can connect various external devices, such as keyboards, mice, printers, etc., to expand the functionality of the devices.

4.Maintenance and debugging:Some sockets may be used for equipment maintenance and debugging, facilitating system updates or troubleshooting for technicians.