How does an ISP work?

Answer 1

That's really an open ended question. Typically, your cable modem connects to a cable modem termination system. From there it's routed to a Broadband Aggregation Router and is then connected to a long haul or 'backbone' such as AT&T.

Answer 2

The ISP is housed in a building called a data center, which contains all of the computing and networking computer that runs the ISP. However, the equipment inside the data center uses up a lot of power as well as generates a lot of heat. If the power from the local utility goes down, the customers will be offline. If there is too much heat generated, equipment may become damaged and stop working permanently. Power from the local utility is supplemented with a backup UPS and diesel power generator system that kicks in automatically when the utility power drops. To deal with the heat generated by the equipment inside the ISP's building, HVAC units are installed which vent cold air evenly around the room to keep a constant temperature and humidity. As equipment gets added, power and HVAC requirements also change which requires the ISP data center manager to order extra power and cooling whenever new networking or computing equipment is added