Traditionally this term refers to an Internet program used to determine whether a specific IP address is accessible or online. It works by sending a packet to the specified address and waiting for a reply. PING (pronounced "ping" as in the game "ping pong") is used primarily to troubleshoot Internet connections. In addition, PING reports how many hops are required to connect two Internet hosts. There are both freeware and shareware PING utilities available for PCs.
Like many great technology terms, this term has morphed into a different spelling and meaning. Seen in email or text messages as "ping me when you get a chance" (not written in ALL CAPS like the acronym) it is used as slang for getting someone's attention. Another example is, "They've decided to fund the project, so make sure you ping Phil to get him on board." To "ping" someone means to send him or her an email or a text message. This new usage has lasting power and is commonly heard everyday in high-tech companies.