The types your thinking of are sinking tips and/or lines. It goes from floating, intermediate (very slow sink), type 1 (little faster), type 2 (little more faster) and up to type 14 which is very heavy sinking. If you do some research on the web you can find out the ips (inches per second) for all the tips. And the head systems are for speys and switch set ups, skagit, scandi....ect Just different applications of spey lines. Im not a big spey fishermen so I cant give in detail the different spey line systems, all I know is Im not half bad at a snap T.