What is a Ping?
Ping is a fundamental program that allows a computer to send a request to another computer somewhere else on the network or on the Internet in order to determine if the computer exists and is responding. A ping sends a packet of data to a specific address and waits for an appropriately named "pong" response. The ping name actually was not derived from table tennis, but was devised from the sound that submarine sonar makes when it bounces off physical objects.
Basic pinging was important in the early browser days when a lot of data was FTP'd (File Transfer Protocol or file uploading) to keep from trying to upload a file to a non-responsive computer. Pinging has also been used to determine the latency, or how long it takes data to travel across the various internet connections and nodes to reach the computer on the other side. This data is then calculated to determine how fast the connection is to the other computer and how quickly a particular data transfer can be completed.
As in the case of many other web technologies, ping has also been utilized for malicious purposes. Ping can be used to render a server inoperable by transmitting a massive number of data packets in a "ping storm" Denial of Service (DoS) attack. Each packet is padded with extra irrelevant data to augment the load on the server until it is overwhelmed and ceases to function.