Shared Lines are groups of phones or devices that share the same number. When the Shared Line phone number rings, all the phones in the group ring, plus you can answer from any device in the Shared Line group. A Shared Line supports one call at a time.
Meanwhile, Call Queues are groups of Users or Extensions that receive queue calls until the receiver becomes available. Most Call Queue functions can support up to 25 calls waiting. These calls stay on hold via Call Park on a single phone number, and they may hear hold music while waiting their turn.