A bug is an error, flaw, or unintended behaviour in computer software that causes it to produce incorrect results or behave unexpectedly. Bugs can range from minor annoyances (like display issues) to critical problems that crash systems or create security vulnerabilities. The term supposedly originated from an actual moth found in an early computer causing malfunction. Developers test software to find and fix bugs before release, but complex programs inevitably have some bugs that slip through. When you encounter software problems, reporting bugs helps developers identify and fix issues. Government digital services undergo extensive testing to minimize bugs affecting public-facing systems.