What ping measures
A ping test sends small packets to a host and waits for replies. The result commonly shows round-trip time, packet loss and whether the host was reachable. Low latency usually means the path is close or fast, while high latency may indicate distance, congestion, wireless issues or routing problems.
Some servers and firewalls block ICMP ping. A failed ping does not always mean a website is offline. It may simply mean the network is configured not to answer ping requests.