PING stands Packet Internet Gopher. This is a utility for ensuring connectivity between computers . ICMP protocol works behind this utility. Under it , sending node sends packets to destination node and reply is received if there is proper communication between two.

PING : Packet Internet Gropper

it's a diagnostic utility , which diagnose devices connectivity.

it use ICMP: Internet Control Messaging protocol to send echo requests ( usually 4 packets) and receive echo replies (4 packets)