"Bug" is computer jargon for an unwanted property of a software program or piece of hardware, especially one that causes a computer to produce incorrect results or to break down.

In software, a bug is an error in coding or logic that causes a program to run incorrectly. Small bugs may not damage information or cause a program to cease functioning, but more serious bugs can cause a program to stop responding to commands (a state commonly called "hang-up") and might even force the user to restart the whole computer, losing unsaved work. The worst bugs can cause damage to saved data, possibly without the user's knowledge. Computer programmers seek to locate and correct bugs by the process known as debugging. Because of the risk to important data, commercial applications are tested and debugged as completely as possible before their release. (In the interest of beating competitors to...