Mac mini won't upgrade beyond 10.7.5

[taralex77]

I believed it was the latest version because if I click Update Software it tells me that there's no update available. Only when I wanted to install XCode 5 I realized that OSX has gone far beyond that and there are 10.8 versions available.

Does anyone know why my mac won't update? is it the maximum possible OS for a Mac Mini 2011 (2.3 GHz i5)?

 

[Intell]

You have to buy Mac OS X 10.8 from the Mac App Store for $20.

 

[GGJstudios]

Software update, upgrade--what's the difference?