what's the difference between the "sage" folder and "sage-5.5" ?

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A couple questions -

I had last year installed an earlier version of sage. I attempted to delete it by deleting the contents of the folder C:\Users\wchen\VirtualBox VMs\

(I'm using windows 7)

Then I also uninstalled the VirtualBox VM via the control panel, and then reinstalled both via the instructions on http://wiki.sagemath.org/SageAppliance

Now after logging into the sage vm using the username/password "sage"/"sage", in the linux console under the path /home/sage, I see two folders, called "sage" and "sage-5.5". The former is highlighted light blue, whereas the latter is dark blue.

As far as I can tell, they both have exactly the same contents, and in particular each contains an executable called "sage".

What is the difference between the two?

thanks,

• will