Download version of SW 2010 - how long is it good for?

We are about to buy a 2010 version of SW from some on-line store and I want to know if this copy is good for only one year or if it is a perpetual piece of software?  I was reading about educational versions and such of SolidWorks and the website doesn't say if this package is an education version or not.  The price is under \$400 so I just have to wonder.

Thanks,

SRC

SolidworksAdministration