What's new in ASP.NET Core 3.0
Microsoft officially announced .NET Core 3.0 on Sep 23, 2019.
Microsoft uses .NET Core to transite Windows-only .NET Framework to a new cross-platform and open sourced .NET technologies.
ASP.NET Core is part of .NET Core.
What's new in ASP.NET Core 3.0?
Please read .NET official website here.