Loopback Interface
The loopback interface is a special, virtual network interface that a computer uses to route network traffic back to itself. Unlike physical network interfaces, such as Ethernet or Wi-Fi, the loopback interface doesn’t represent any actual hardware.
The most common IP address used for the loopback interface is 127.0.0.1 for IPv4 and ::1 for IPv6. Any connection attempts to these addresses will be looped back to the local machine. For example, if you open a web browser and go to http://127.0.0.1, the browser will try to connect to a web server running on your own computer.
ping 127.0.0.1