You are driving over a long bridge during bumper to bumper rush hour traffic. The vehicle behind you suddenly turns on his flashers and siren. Yes, he has priority but he can't get around you and you can't pull over short of crashing through the barrier and falling into the river. That is buffer bloat.
Same scenario but now you're on an expressway that has a shoulder for emergencies. You're locked in traffic and can't really move out of the way but the emergency vehicle takes to the shoulder of the road and bypasses the gridlock.
By dedicating the shoulder for emergencies we may have contributed to the gridlock as that lane was unavailable for traffic (let's call it a bandwidth limiter) but it did its job when we needed it.
By giving some vehicles flashers and sirens we have implemented QoS, that is we're giving some traffic priority, kind of like "Fast Pass" at Disney.
If you're not having any problems (e.g., no buffering when streaming, crappy Internet while kids are gaming) don't worry about it.
If you are having trouble then you will want to read up on setting QoS (Quality of Service, flagging important traffic) and bandwidth limiters (telling your router you have less bandwidth than you really have so you can get out an emergency packet or two) for your router. Towards that here is a link to an early
"Toastman" article.
