Dictionary.net

1.fixing the problems in a software when it crashes, acts strangely, or is hacked. Refer to bug. 2. fixing existing errors or potential errors in a system to make is good for sale.

The process of attempting to determine the causeof the symptoms of malfunctions in a program or other system.These symptoms may be detected during testing or use by realusers.Symptoms are often caused by factors outside the program, suchas misconfiguration of the user's operating system,misunderstanding by the user (see PEBCAK) or failures inother external systems on which the program relies. Some ofthese are more in the realm of technical support but need tobe eliminated. Debugging really starts when it has beenestablished that the program is not behaving according to itsspecification (which may be formal or informal). It can bedone by visual inspection of the source code, debugging byprintf or using a debugger. The result may be that theprogram is actually behaving as specified but that the spec iswrong or the requirements on which it was based were deficientin some way (see BAD).Once a bug has been identified and a fix applied, the programmust be tested to determine whether the bug is really fixedand what effects the changes have had on other aspects of theprogram's operation (see regression testing).The term is said to have been coined by Grace Hopper, basedon the term "bug".