What is .NET Framework and .NET Core?

What is .NET?

.NET is Microsoft's development platform for building apps with C#, F#, and VB. It includes a runtime, libraries, and tooling.

Framework vs Core vs .NET 5+

	.NET Framework	.NET Core / .NET 5+
Platform	Windows only	Cross-platform
Open source	No	Yes
Status	Legacy/maintenance	Active, future

Since .NET 5 (2020), the names merged into just ".NET" — cross-platform and open source. Use it for all new projects.

What You Can Build

• Web — ASP.NET Core.
• Desktop — WPF, WinForms, MAUI.
• Cloud / APIs — microservices on Azure.
• Mobile — .NET MAUI.

FAQs

Should I learn Framework or .NET 8?

Learn modern .NET (8/9) — Framework is legacy. More in our .NET guides.

Is .NET free?

Yes — fully open source under the .NET Foundation.