Standard login flow with credential validation and error handling demonstrates the core authentication pattern used across web and mobile applications. User input flows through validation logic with a decision gate that branches to either menu access or error messaging. This architecture ensures secure credential verification while providing clear user feedback on authentication success or failure. Fork and customize this flowchart on Diagrams.so to match your application's specific authentication requirements, including multi-factor authentication or social login steps. The retry loop from error state back to input collection represents best-practice user experience design for authentication interfaces.