Visitor Location Register

Definition
The Visitor Location Register (VLR) is

"[t]he location register other than the Home Location Register (HLR) used by a Mobile Switching Center (MSC) to retrieve information for handling of calls to or from a visiting subscriber. The VLR may or may not be located within, and be indistinguishable from, an MSC. The VLR may serve more than one MSC."