ASP.NET Core And Benefits

Originally deemed ASP.NET vNext, the framework was going to be called ASP.NET 5 when ready. However, in order to avoid implying it is an update to the existing ASP.NET framework, Microsoft later changed the name to ASP.NET Core at the 1.0 release.

source https://www.c-sharpcorner.com/article/asp-net-core-and-benefits/