Hi TIIIIIIIIIIT,
Internet Control Message Protocol (ICMP) is a sub-protocol in the TCP/IP protocol suite. It is a network-layer protocol and is used to transmit control information between hosts and routers, including error reporting, exchange of restricted control information, and status information. ICMP messages are automatically sent when the IP data cannot access the destination or the IP router cannot forward data packets at the current transmission rate. You can run the ping command to send ICMP request messages and record the received ICMP response messages. These messages can be used as a reference for troubleshooting network or host faults.
I hope it helps!