ASP.NET is a unified web development model integrated with .NET framework, designed to provide services to create dynamic web applications and web services. It is built on the Common Language Runtime (CLR) of the .NET framework and includes those benefits like multi-language interoperability, type safety, garbage collection and inheritance.

They have some the major differences from ASP, an earlier version of ASP.NET. The object model of ASP.NET has thus significantly improved from ASP, which makes it fully backward compatible to ASP

These differences included:-

1. Usage of compiled code (instead of interpreted code),
2. Event-driven server-side scripting model,
3. State management,
4. Rapid application development using controls and libraries of the .NET framework.
5. Dynamic programming code is placed separately in a file or specially designated tag. This avoids the program code getting modified during runtime.

ASP.NET works with the Internet Information Server (IIS) to deliver the content in response to client requests. While processing the requests, ASP.NET provides access to all .NET classes, custom components and databases, similar to that of a desktop application.

.NET Framework

A programming  infrastructure created by Microsoft  for building, deploying, and running applications and services that use .NET technologies, such as desktop applications and Web services.

It includes a large library and provides language interoperability across several programming languages. Programs written for the .NET Framework execute in a software environment, known as the Common Language Runtime.