Recordings feature heading

Calls within Team can be joined by anyone on the Team unless private. Calls within Channel can be joined by any member of the channel. Recordings for one on one calls are available to participants only while recordings in channels are available to all channel members even if they did not participate.  

Private Channel Recordings
Playback is only available to members of a the private channel. Only members of said channel have access to these type of recordings, not the entire team. A member of a private channel does not need to participate in a conversation in order to have access to it.
Private Personal Recordings
All one to one calls produce a recording. If the call was selected to be private (at the origination or during a call) then the recording will only be available to its participants and no one else.
Public Channel Recording
Playback is available to all on your team. These recordings are typically a result of a watercooler conversation that was not made private or a conversation that took place in a public channel.