PHPStan is a static analysis tool for PHP code. It's used to detect potential errors, incorrect types, unreachable code, and other issues in PHP code before the program runs.
Essentially, PHPStan helps developers enhance the quality of their code by flagging potential errors and issues that might occur during runtime. It checks the code for type safety, variable assignments, invalid method calls, and other possible sources of errors.
By integrating PHPStan into the development process, developers can make their codebase more robust, improve maintainability, and catch bugs early, ultimately leading to more reliable software.