Microsoft has re-branded its open source web framework ASP.NET 5 To ASP.NET core 1.0. Going forward, ASP.NET 5 will be knows and ASP.NET core 1.0 , .NET Core 5 will be known as .NET core 1.0 and Entity framework known as Entity framework core 1.0 (EF core 1.0)
Microsoft Principal Program Manager Scott Hanselman introduced the new names on his blog on January 19 . Unveiled the new names on his blog on January 19 with preceding diagram.
Why new names ( ASP.NET core 1.0 & .NET core 1.0) ?
The whole .NET core concepts are new. .NET core has a completely new command line interface (CLI). Now .NET 4.6 is the full and stable version and Microsoft still working with .NET core version .
Read the full article from http://www.hanselman.com/blog/ASPNET5IsDeadIntroducingASPNETCore10AndNETCore10.aspx