Jitter - Jitter is the deviation in or displacement of some aspect of the pulses in a high-frequency digital signal. As the name suggests, jitter can be thought of as shaky pulses. The deviation can be in terms of amplitude, phase timing, or the width of the signal pulse. Another definition is that it is "the period frequency displacement of the signal from its ideal location." Among the causes of jitter are electromagnetic interference (EMI) and crosstalk with other signals. Jitter can cause a display monitor to flicker; affect the ability of the processor in a personal computer to perform as intended; introduce clicks or other undesired effects in audio signals, and loss of transmitted data between network devices. The amount of allowable jitter depends greatly on the application.
JPEG (Joint Photographic Experts Group) - A JPEG is a 24 bit bitmap image format that can be a very efficient way to compress graphics for web sites due to its use of lossy compression. You can select how much to compress a file, and therefore how much information is lost. The JPEG format does not support animation or transparency. JPEG images use the .jpg file extension.
JSP (JavaServer Pages) - JSP pages provide a simplified, fast way to create web pages that display dynamically-generated content. You can use JSP tags or scriptlets to generate the dynamic content. The logic that generates the content is encapsulated in tags and JavaBeans components and tied together in scriptlets, all of which are executed on the server side. On the server, a JSP engine interprets JSP tags and scriptlets, generates content (for example, by accessing JavaBeans components, accessing a database with JDBC technology, or including files), and sends the results back in the form of an HTML (or XML) page to the browser. The function of JSP is similar to ASP, however, JSP is an open standard.
Jumpers - A metal bridge that closes an electrical circuit. Typically, a jumper consists of a plastic plug with metal contacts inside that fits over a pair of protruding pins. Jumpers are sometimes used to configure expansion boards, hard drives, and other devices. By placing a jumper plug over a different set of pins, you can change a board's parameters.