more seriously: if server and client are the same computer, then you can access LimeSurvey via localhost even if you can't "connect to Internet". Same if server and client are 2 different computers on a same local network even if that network is not connected to the rest of the world.
On a PC you can create a local installation using XAMPP. Same can be done on a Mac (using Mamp) and of course it can also be done (not tested by me) on a Linux computer.
That way you can have a local installation. But without connection to the Internet you cannot:
send out invitations
send out notifications
and some other things that you might want to do. But I have had a use case where having a local installation was very helpful.
Tammo ter Hark
Tammo ter Hark at Respondage
For Limesurvey reporting, education and customized themes
respondage.nl