波动高点和低点 (Swing Hight And Lows)

A lot of the web. writes, speak about swing hights and lows.
but it seems to be just a side thoughts to other systems
but is there a system that just uses highs & lows out there?
I don't see one on the treads here

the 3 ducks there is talk about it but its never really explained.
The writes of this system got in on a break

does anyone have some information. or a web I can go to?

thank you