Cross-platform compatibility allows .NET applications to run seamlessly on Windows, macOS, and Linux. The shift from .NET Framework to .NET Core and .NET 5+ ensures flexibility, portability, and broader device support. Without cross-platform compatibility, applications are limited to specific environments, reducing their reach. Technologies like Xamarin (for mobile), Blazor (for web UI), and MAUI (for cross-platform applications) enable Dot Net Development to create versatile applications. This flexibility helps businesses reduce development costs, maximize reach, and ensure consistent performance across different platforms, making it an essential factor in modern .NET development.