What exactly is DOCSIS with reference to a cable modem?

DOCSIS is a way to provide data over cable TV lines. DOCSIS 1.0 from 1997 standard, and defined how IP traffic could co-habitate with analog TV signals. DOCSIS 1.1 in 1999 added Quality of Service (QoS) to prioritize different types of traffic (like VoIP). DOCSIS 2.0 increased download speeds. And DOCSIS 3.0 increases upload and download speeds and adds IPv6 support. DOCSIS 3.0 is capable of over 300Mbps downloads!!