A bug report is a document created to inform developers about issues or errors in a software application. It typically includes details such as the steps to reproduce the problem, the expected outcome, and the actual outcome. This information helps the development team understand and fix the issue efficiently. Bug reports are essential for maintaining software quality and improving user experience. They can be submitted by users, testers, or developers and are often tracked using tools like JIRA or Bugzilla. Properly written bug reports contribute to faster resolution times and better overall software performance.