Which SharePoint version do I have installed?

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:

You have to dig the registry
Use PowerShell

Registry method

Open Regedit
Navigate to HKLM\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\15.0\WSS\InstalledProducts
Compare the guids with the list

PowerShell method

Open SharePoint management Shell
Type the comment “(Get-SPFarm).Products” (without the quotes)
Compate the guids with the list

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