Reading from Wikipedia:
A debugger or debugging tool is a wikipedia:computer program that is used to test and wikipedia:debug other programs (the "target" program). The code to be examined might alternatively be running on an instruction set simulator (ISS), a technique that allows great power in its ability to halt when specific conditions are encountered but which will typically be somewhat slower than executing the code directly on the appropriate (or the same) processor. Some debuggers offer two modes of operation - full or partial simulation, to limit this impact.
Using a debugger, you can analyse the source of bugs in your code more quickly.
List of Recommended Debuggers Edit
GDB, short for the GNU Debugger, is an open-source command line debugger that can be used to debug programs in C, C++ and for other languages. GDB has several graphical front-ends, such as DDD (DDD's homepage).