Bandwidth Allocation Protocol? How is traffic prioritized and configured?

A) Happy National VPN Concentrator Appreciation Week

B) There are major rolling internet outages being reported by users to providers all around the country. Barring their VPN issues and such - I assume that this is because 'residential' internet is optimized for *prime time* hours (4pm-11pm) and is not setup to essentially handle 'business' traffic during business hours. I use 'quotes' because I am assuming all of this traffic travels along the same hardware (ie regional cabling, etc) but is somehow optimized/prioritized through software by the telecom provider.

C) Am I correct in that assumption? Can you explain (like I am maybe 10) how this works? What protocols/etc are used?

Thanks!