A bug report, also known as a defect report or issue report, is a document that describes a problem or error found in an application. The purpose of a bug report is to provide detailed information about the issue, allowing developers, testers, and other stakeholders to reproduce, diagnose, and fix the problem.

Bug reports can be categorized into different types, such as:

1. Crash or freeze: The application crashes or freezes when performing specific actions.
2. Logic error: The application produces incorrect results or behaves unexpectedly.
3. User interface (UI) issue: Problems with the layout, rendering, or interaction of UI elements.
4. Performance issue: Slow performance, delays, or excessive resource usage.

Companies that compete in the bug reports space usually provide tools that make it easier to capture details about a bug and organize reports in a way that makes it easier for developers to fix the issues.