Here are some Call Center or Telecomm Terminology links. The first one is probably the most useful.
When you get into specific system terminology, such as Definity, VDNs, etc... It can be difficult to find.
Definity is a Lucent brand of switch (telephone system).
VDNs are the call flows that you build to route your calls in a particular way. I found this useful conversion, if you are used to any other phone switch. It lists the switch name and then what the call flows are called:
Alcatel 400: Pilot
Aspect Call Center: Application (Also CCTs or Call Control Tables)
Ericsson ACP1000: Trunk group/called number
Lucent DEFINITY ECS: Vector Directory Number (VDN)
NEC NEAX 2400: CCV number
Nortel DMS-100: Primary or Supplementary ACD DN
Nortel Meridian: ACD Directory Number (ACD DN) or ACD Controlled Directory Number (ACD CDN)2
Rockwell Galaxy: Gate
Rockwell Spectrum: Application
Siemens Hicom 300 E: ACD Routing Table (ART)
Siemens Rolm 9005: Pilot number for ACD routing table
I'll also send this to you in email, but other people might also be interested in it.