Augur websocket endpoints

I'm installing Augur, https://www.augur.net/ for the first time.

These are all websocket endpoints. I'm trying megageth now and I'm 55% synced.
wss://mainnet.infura.io/ws
http://megageth.com/ethereum-http
ws://megageth.com/ethereum-ws
http://gethstar.com/ethereum-http
ws://gethstar.com/ethereum-ws

At first I had no idea what a websocket endpoint was, but then I went on Augur Discord and a nice person Xeno helped me out. He had me clear C:\Users\xxx\AppData\Local\Programs\augur\ and retry with megageth or gethstar.

I don't know what these services are. I searched infura and found a lot of info, but I still don't understand it. I tried searching megageth and gethstar and found nothing.

Is it a copy of the ETH blockchain full node, but formatted into a smaller more streamlined nosql database style? I hope asking questions on Steem is ok. I'm providing the information I can and asking the rest.