Microsoft's .NET is a free, open-source framework that provides .NET support on multiple platforms.

.NET started as the .NET Core implementation, a rewrite of the .NET Framework. .NET Core (version 1 to 3.n) and the .NET Framework (up to versions 4.n) were different offerings. .NET Core was renamed to .NET in its version 5 and .NET versions 5 and later are the successor of the .NET Framework.