.NET Framework is a software development platform developed by Microsoft, primarily running on Microsoft Windows. Coursera's .NET Framework catalogue allows you to delve into the world of .NET programming, expanding your understanding and capabilities in creating web applications, services, and mobile applications. You'll learn about the key aspects of the .NET Framework such as ASP.NET, ADO.NET, Windows Forms, and Windows Communication Foundation (WCF) among others. Mastering this skill will allow you to build robust, secure, and scalable applications in various sectors from e-commerce to enterprise-level systems.