Federated video hosting software. Like lots of Youtube alternatives it seems to be mostly used by fuckwads, but some decent instances are:
The idea is that you can't really outdo Youtube because of how big it it, you can't match their speed and size, unless you're rich. With Peertube videos can be streamed via torrent, so bandwidth is theoretically shared. Of course, if an instance is small, then noone else has the file to share with you, so you're just streaming it from the instance anyway.