A key feature of the protocol is that waves are stored on the service provider's servers instead of being sent between users. Waves are federated; copies of waves and wavelets are distributed by the wave provider of the originating user to the providers of all other participants in a particular wave or wavelet so all participants have immediate access to up-to-date content. The originating wave server is responsible for hosting, processing, and concurrency control of waves.   The protocol allows private reply wavelets within parent waves, where other participants have no access or knowledge of them.  
I recall when I was first diagnosed with asthmatic bronchitis, I had pneumonia and didn’t know it, made a regular clinic appointment for what I assumed was just my normal bronchitis, and my 02 was like 78. I walked into the room and the nurse took one look at me, left the room to get the pulse ox, came back and measured it. Got that level, and went to get the oxygen tank. I was actually terrified. I had noticed I was out of breath a lot, and that I needed to sit down after walking across the room or up the stairs, etc. But I didn’t think it was that bad! They also nebbed me that visit.