As a tech writer, I know that pressing Option-Y on my keyboard will give me a ¥ symbol, and that Option-K will add a little degree circle˚ to my article. I even know how to add umlauts (handy for death mëtal band names – just press Option-U and then type a letter) and accents (good for clichés – like an umlaut but using Option-E).
But what about the Apple logo, the copyright symbol, or any of those other essential but seldom used characters? That’s what Characters is for.