A debugger is a special tool used by programmers to find and fix errors, or "bugs," in their code. When a program doesn't work as expected, a debugger helps identify where things went wrong. It allows developers to run their code step by step, examine variables, and see how the program behaves in real-time. This makes it easier to understand the flow of the program and locate issues. Using a debugger can save a lot of time and frustration. Instead of guessing what might be wrong, programmers can pinpoint the exact line of code causing the problem. This leads to more efficient coding and better software, ultimately improving the user experience.