A mode contains your pattern of discrimination, plus your other preferred settings, such as deep on or off, high trash, fast on or off etc. So whenever you select that mode it will always have these settings automatically. You can have four modes, one of mine is the standard coin pattern opened up a bit, another is my Two Tone Ferrous set up and a couple of others specifically set up for places I hunt often. A pattern is just that a discrimination pattern. You can create your own, by discriminating out items or accepting others, there are many ways to set up a pattern. A pattern carries none of your preferred settings with it but will use the one's out of a mode. Simple explanation, you are running a mode in which you have deep off, fast on, high trash, difficult ground, multitones etc, while in this setup you can hit menu and arrow over to discrimination, go down to select hit that and select a pattern, hit your detect button and it will set up that pattern using the preffered settings that you were last using in the mode you were in. I am sure that there are those that can make it clearer than I can but the concept is easy to understand once you try it.