In Networking, Jitter is the variation of the
latency of
ping times.
Let me clarify that.
To understand jitter, first you must understand ping. When you are trying to check the reliability and availability of a connection, you use a tool called ping. In DOS or a command line (just about any one out there), type in "ping yahoo.com" and your computer will send a short packet over the internet to whatever computer Yahoo is on, and the computer at the other end will send a return packet. The computer calculates the delay it took in milliseconds to get there and back. So a ping is like an echo.
Timing the ping reveals the latency of a connection, or how long it takes for the ping to make a round trip. The variation of this latency is known as the jitter. Imagine if you graphed ping times by pinging every second and showing the change in time. You can see the jitter by changes in this graph.
Jitter is very important to network connections, since certain applications are very sensitive to it. Telemedicine is one example; if you're performing a remote surgery then your patient's life may depend on a reliable connection with very low jitter.
Jitter is relatively difficult to monitor, since just pinging wouldn't be very detailed. One scientist has developed an idea to turn jitter into an audible sound which you can monitor yourself. A ten-millisecond ping would give you a 100Hertz tone by your computer. The longer the time, the lower the pitch. Listening to that would make it extremely easy to diagnose your connection. If the sound started skipping like a CD player, then you can tell there's a problem. If the jitter changes, then you can clearly hear the tone warble.
Read more of this idea at http://www.newscientist.com/news/news.jsp?id=ns99993112
Also, Jitter is also a kind of
tremble, a
shake, an
anxiety, a
paranoia. Jitter is usually pluralized as
jitters