The EDIUS licence lets you use EDIUS on one machine at a time. You are allowed to install it on two computers, but you are only supposed to use one machine at a time. If you are using your copy of EDIUS on two computers at the same time you are breaking the licence agreement; you should buy two copies if you are planning to use both at the same time. You can activate your copy of EDIUS twice and deactivate it twice in one month. . If you loose all your activations because a computer has crashed or been re-installed then you will need to contact Grass Valley support to get your serial number re-enabled.
This is fairly similar to other editing programs. Avid will only let you have one activation although you can activate/deactivate as much as you want; Premiere lets you have 2 activations, and with the Creative Cloud you can log in and out of the software when you need to.
EDIUS Pro 9 needs to connect to the internet once a month to validate the licence.
In early versions of EDIUS you did not need to connect to the Internet at all, and used a USB dongle to licence the software; since EDIUS 6.5 the software has been activated over the internet. With EDIUS Workgroup this only needs to be done once and you never need to connect to the internet again. There is also an offline activation feature.
EDIUS Pro has to be activated via the internet and has to check the licence once a month via the web. If you do not do this the program will stop working until it can be validated. This does not cost any money and if your computer is on the internet permanently you may not even notice. If you do not use your computer for 2 or 3 months this is not a problem. You will need to connect to the internet to reactivate EDIUS when you next start the computer but the fact that you did not use connect for a couple of months is not an issue. You also need to create an "EDIUS ID", which is a very simple process, just like creating a webshop account.
If you do not want to connect your machine to the Internet or are not allowed to then you will need to buy the Workgroup version.
EDIUS Workgroup 8 does not need to connect to the internet
You can activate EDIUS Workgroup using the offline activation and then you never need to connect to the Internet with the EDIUS computer again.
There are definite advantages of connecting your machine to the Internet and making a Grass Valley EDIUS ID to register and activate your software, but with the Workgroup version you do not need the EDIUS machine to be on the internet. There are quite a few differences between Workgroup and Pro which are mainly aimed at giving more broadcast-oriented features in the Workgroup version. There is a full list of the differences between the Workgroup and Pro versions below.