The 12-factor App is a methodology for building SaaS apps – https://12factor.net/
Note the point…
.NET 5.0 is the next major release of .NET Core following 3.1. We named this new release .NET 5.0 instead of .NET Core 4.0 for two reasons:
- We skipped version numbers 4.x to avoid confusion with .NET Framework 4.x.
- We dropped “Core” from the name to emphasize that this is the main implementation of .NET going forward. .NET 5.0 supports more types of apps and more platforms than .NET Core or .NET Framework.
ASP.NET Core 5.0 is based on .NET 5.0 but retains the name “Core” to avoid confusing it with ASP.NET MVC 5. Likewise, Entity Framework Core 5.0 retains the name “Core” to avoid confusing it with Entity Framework 5 and 6.