system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: There are about 900 Channels on my TV. Who is running/watching all of these obscure channels?
gpt
Many of those channels are:

HD versions of normal channels, with the exact same content.

Robo channels that don't have content, such as a "TV guide" built 
into your cable box.

Robo channels with music provided by your cable co.

Alternate language versions of normal channels.

Foreign channels.

What's left is just a bunch of channels, and TV companies run them.  Many of them play simply syndicated shows that are all repeats and don't actually produce any content.  There are dozens of crappy news shows for specific subjects ("TechTV", etc).  Then there are channels which literally just show infomercials 24/7 (Home Shopping Network).