.NET + C# is a powerful software stack for developing web applications, desktop applications, and mobile applications. .NET is a comprehensive development platform created by Microsoft. It provides an extensive library of code, tools, and technologies to help create powerful software applications. C# is a general-purpose, object-oriented programming language designed by Microsoft to work with the .NET framework. It is a versatile language that can be used to develop applications for the web, desktop, and mobile devices. Together, .NET and C# provide a comprehensive development environment for creating robust and reliable software applications. C# is a popular choice for developers due to its powerful features and flexibility. It is a great choice for any type of development project, from small applications to large enterprise systems.