Call forwarding or Simultaneous Ringing are good solutions when you know the extensions or phone numbers where you will be moving to. But what if you need to move to another office location in a middle of a call and don't know the number over there? This is when Call Park would be your go-to feature.
When using Call Park you basically puts a call on hold in a system-wide "parking" area. The call can then be retrieved from any phone in the office. In practice what happens when you press the Call Park button is that the system will move the call to a designated parking area and assign a special virtual extension to this parking spot. The system will tell you this extension and you can hang up your phone. You can then retrieve the call from any other phone in the office by dialing the relevant virtual extension. Until you retrieve the call, the caller will be hearing music as if on a regular hold session. It is possible to assign an access code to the parked call in case you want to make sure you are the only person who can retrieve it.
Call Park is also a great feature to increase responsiveness to callers. For example, if a client calls and ask to speak to a specific agent who happens to be busy with another call. If a co-worker who picked up the call will transfer the call to the agent he may end up in the agent's voicemail (depending on overflow rules for the system) - which some clients find frustrating. Instead the co-worker can park the call, and notify the agent he has a call waiting for him.
A variation on this scenario is useful in stores, warehouses or supermarkets where employees are not bound to their extensions or many of them share a phone to receive occasional calls. For example a receptionist receives a call in a car shop. She will park it and make an announcement using the speakers system (that also happen to be integrated into the phone system) letting one of the mechanics know they have a call, that he can retrive from the nearest phone next to him. John can than retrieve it from the nearest phone next to him.