Prior to Parallels Version 11 you were able to use the Parallels software on any of the Macs you owned and used for non-commercial work. With Version 11 you are no longer allowed to do this. So you need to purchase a license key for each and every Mac.
VMWare Fusion has a completely different policy that states the following:
Can I use a single license on more than one Mac?
VMware Fusion for personal use:
You may install and use VMware Fusion for personal, non-commercial use on any Apple-branded products running Mac OS X (“Mac Computer”) that you own or control.– See more at: https://www.vmware.com/support/fusion/faq/licensing.html#sthash.Y452Lrq1.dpuf
I’m going to ask Parallels for a refund and make the move to VMWare Fusion. Don’t get me started on Parallels annoying pop-up dialogs.
Bruce Elgort 
There are more things to be aware of, like all the features that were removed from the Standard edition and are now only available in the ‘Pro’ edition. That Pro edition is only available through a yearly subscription model (costing 99 euros/year in the Netherlands). Really bad move, and I’m considering Fusion too.
Here are a couple that I know of:
– Network settings
– Rollback function
– Limitation on the max no of CPUs/ RAM
More info here:
– https://forum.parallels.com/threads/missing-network-settings-dhcp.329417/
– https://forum.parallels.com/threads/parallels-11-rollback-feature-missing-why.329289/
– http://kb.parallels.com/en/123296
There’s also a difference between Fusion and Fusion Pro – similar to what you see w/ Parallels (snapshots, NAT mgmt, etc). They made a similar shift to the feature set in v7. But it is a purchase for Fusion and not a subscription.
Std/Pro comparison found here: http://www.vmware.com/products/fusion/compare.html#table2