ASP.NET is an open source web framework, created by Microsoft, for building modern web apps and services with .NET.
ASP.NET is cross platform and runs on Windows, Linux, macOS, and Docker.
.NET is a developer platform made up of tools, programming languages, and libraries for building many different types of applications.
The base platform provides components that apply to all different types of apps. Additional frameworks, such as ASP.NET, extend .NET with components for building specific types of apps.
Here are some things included in the .NET platform:
ASP.NET extends the .NET platform with tools and libraries specifically for building web apps.
These are some things that ASP.NET adds to the .NET platform:
When using ASP.NET your back end code, such as business logic and data access, is written using C#.
Because ASP.NET extends .NET, you can use the large ecosystem of packages and libraries available to all .NET developers. You can also author your own libraries that are shared between any applications written on the .NET platform.
Razor provides a syntax for creating dynamic web pages using HTML and C#. Your C# code is evaluated on the server and the resulting HTML content is sent to the user.
ASP.NET apps can be developed and run on Windows, Linux, macOS, and Docker.
The Visual Studio family of products has tools for building .NET apps on any operating system. There are also command line tools and extensions for many popular editors.
ASP.NET allows you to build many types of web applications, including web pages, REST APIs, microservices, and hubs that push real-time content to connected clients.
If you use ASP.NET, you'll soon come accross the term ASP.NET Core.
ASP.NET Core is the open-source and cross-platform version of ASP.NET. You should use ASP.NET Core for all new applications. The tutorials on this site all use ASP.NET Core.
The Windows-only versions of ASP.NET, that existed before ASP.NET Core, is typically just referred to as ASP.NET. The majority of innovation occurs in ASP.NET Core, but other versions continue to receive minor updates and bug-fixes.