LOL! Hey, the audiophile is actually a pretty damn decent card for the money, don't knock it.
It's WORD clock, not world clock, if there is a world clock, then I want to know what it is too
I think we may have to ask the Mayans about that one..
Word clock keeps digital devices in sync, by means of a master and slave relationship. You don't need to worry about it unless you have gear that is using digital connections.
If you have your 2496 say, and one other piece of digital gear, like a stereo effects box that connects via s/pdif, then you decide which is going to be the master clock, and which is the slave, make the appropriate settings in each device and they will then pass digital audio back and forth in perfect sync.
Without that sync, you will get some serious nasty white noise at worse, or really ****ing annoying clicks and snaps at best.
You can sync more than 2 devices from one master device if it has the necessary amount and type of digital outs to connect everything, but usually people buy a dedicated word clock whose sole function is to send the clock signal to all the digital devices in the system and keep them playing nicely together.