.NET is a software development framework and ecosystem designed and supported by Microsoft to allow for easy desktop and web application engineering. .NET best suits businesses that look for a wide range of features like web-based services, desktop software, and cloud infrastructure support
.NET comes in four flavors: .NET Framework, .NET Core, Xamarin, and Universal Windows Platform (UWP).
These implementations combined are called the .NET development platform. Each of them contains frameworks and libraries to build various applications.
It includes three main application models – WPF, Windows Forms, ASP.NET Forms – and Base Class Library.
You can build many types of apps with .NET. Some are cross-platform, and some target a specific OS or .NET implementation.