These options are found in Settings > Transfers > Peers
It is recommended to leave all four options active.
This is BitTorrent version 1. This is the original protocol, with several extensions such as PEX, holepunching, Fast Extension, and others.
This is BitTorrent version 2, as described in BEP-52. This protocol is more complex, and is unfortunately not well supported in other clients at this time.
Web Seed HTTP
This will allow the use of http: URLs as peers, otherwise known as a web seed.
Web Seed HTTPS
This will allow the use of https: URLs as peers, otherwise known as a web seed.