There is no easy way to find out what SharePoint 2013 Edition you are running. You can do it by doing one of two things:
Registry method
PowerShell method
GUIDS:
C5D855EE-F32B-4A1C-97A8-F0A28CE02F9C - SharePoint Server 2013 CBF97833-C73A-4BAF-9ED3-D47B3CFF51BE - SharePoint Server 2013 Preview B7D84C2B-0754-49E4-B7BE-7EE321DCE0A9 - SharePoint Server 2013 Enterprise 298A586A-E3C1-42F0-AFE0-4BCFDC2E7CD0 - SharePoint Server 2013 Enterprise Preview D6B57A0D-AE69-4A3E-B031-1F993EE52EDC - Microsoft Office Web Apps Server 2013 9FF54EBC-8C12-47D7-854F-3865D4BE8118 - SharePoint Foundation 2013 35466B1A-B17B-4DFB-A703-F74E2A1F5F5E - Project Server 2013 BC7BAF08-4D97-462C-8411-341052402E71 - Project Server 2013 Preview