Dicing up price into separate components allows us to make sense of, and bring clarity to what might otherwise seem like noise to the rest of the world. I all boils down to opportunity and opportunity comes through structure.
There are a lot of price patterns out there; oftentimes, more than we care to have but regardless, and as my mother used to say “organization is the key to success” (and a couple other things).
If you're looking for a concise overview on common price patterns I recommend you check out Thomas Bulkowski's site. Tom has written more than a few books on the subject including “The Encyclopedia of Chart Patterns” found on my Book Shelf.
They're just good to know, use, and have as a reference in the back of your brain. Tom has a thorough site which includes a visual index you can find by pointing your browsers here: