Installing Vectorworks and running Vectorworks are two different kinds of actions. While you can so most tasks in Vectorworks without constant internet access, you will be required to or want to access to the internet at various times. Please read below for more information.
Installing Vectorworks
It is possible to install Vectorworks (from a CD/DVD prior to version 2017, or from a USB stick version 2017 and later) without using the internet. However you may not be able to initially launch and run the software until you have an internet connection, because the software must "activate" before it can be used. Also, without an internet connection during installation you will not be able to access the majority of the Vectorworks Content libraries if you would like to download them when first getting set up.
Running Vectorworks - This depends on the kind of Vectorworks license you have.
For E series versions of Vectorworks (most users have E series):
When you first run Vectorworks it must be able to connect to the internet to “activate”. There is no way around this. Vectorworks will regularly need to reset its activation certificate, so you will see an activation message again if you computer is not connected to the internet for a significant period of time. If you see this message, simply make sure you are connected to the internet and allow Vectorworks to check its activation. After Vectorworks activates, it can be run without an active internet connection for a period of time prior to needing a reactivate.
For B series versions of Vectorworks (which use a hardware dongle):
You will be able to install and launch Vectorworks without access to the internet. You must have the hardware dongle attached to your computer at all times you run the software..
Most Vectorworks Content Libraries are accessed through an internet connection:
Keep in mind that when you purchase Vectorworks you also get access to many great symbols. The the basic Vectorworks installer contains a small quantity of default libraries, however the majority of Content libraries are accessed via the Package Manager (to download en masse in large chunks) or through the Resource Manager (to browse and download as they are needed.) If you do not have internet access, you will not be able to download or access these resources.
Vectorworks updates (Service Packs):
Occasionally Vectorworks will check for updates (Service Packs) over the internet. You will require internet access to download and install these Service Packs. Please ensure that you update Vectorworks when Service Packs are released, in order to make sure you are using the most up-to-date version available.