What does pinging an IP address actually prove?¶

A ping sends an ICMP message and records whether a reply returns from the tested address or associated infrastructure.

A reply¶

A response shows that something answered at that time. It might be the intended host, but it could also be a router, firewall, load balancer or other shared component. It does not prove that a website, account or application was active.

No reply¶

Silence proves only that no reply was received. ICMP may be blocked while ordinary web or application traffic is allowed. The host may also be offline, rate-limiting or configured not to respond.

Both results are time-specific. Address allocation and cloud infrastructure can change after the event. Active testing also creates traffic that may be logged, so use it only for a defined and authorised purpose.