J. Random Hacker - In IT parlance, J. Random Hacker is a mythical figure, a kind of “Joe Sixpack” or “John Doe” of the IT world. The name has been used as a pseudonym for authors, a cliche in talking about IT security, and in certain types of placeholder situations, for example, in name or title fields in a database.

Jaggies - Jaggies is a term for various kinds of anomalies in computer graphics outputs or display imaging. The result displays shape edges composed of small squares or “steps” instead of a smoothly contoured line.

JAVA - An object-oriented programming language developed by Sun Microsystems. Programmes authored in Java do not rely on an operating system, as long as Java Virtual Machine (JVM) is installed on the device on which they are running.

JAVA script - JavaScript is a programming language that is mostly used in web pages, usually to add features that make the web page more interactive. When JavaScript is included in an HTML file it relies upon the browser to interpret the JavaScript. When JavaScript is combined with Cascading Style Sheets (CSS), and later versions of HTML (4.0 and later) the result is often called DHTML.

 J-cut - A J-cut is a type of cut in which the sound of the next scene precedes the picture. The name comes from the shape these clips make in the timeline of an editing program.

Jelly Bean - The 4.1 version of the Android™ operating system.

JPEG (Joint Photographic Experts Group) - Standard web graphic file format that uses a compression technique to reduce graphic file sizes

Jump Cut - Jump Cut is an abrupt transition, typically in a sequential clip that makes the subject appear to jump from one spot to the other, without continuity.

Jump page ad - microsite which is reached via click-through from button or banner ad. The jump page itself can list several topics, which are linked to either the advertiser's site or the publisher's site.

Junk E-mail Folder – A folder within an e-mail client or on an E-mail Service Provider server that stores e-mail messages that are identified, either by the user or by an automated spam filter, as undesired or undesirable.