AdWords has sort of become a keyword research and opportunity tool of choice for SEO and, of course, PPC folks for a decade now. We've always had some optionality around how we choose keywords inside of AdWords. Say I was selling groceries online. Maybe I'm selling Asian groceries online and, specifically, fish sauce, and I want to do some modifications to which terms and phrases I bid on. So I could use things like these brackets to say exact match only, bid on keywords that are precisely fish sauce, no modifiers, no changes, not fishes sauce, not fish sauces, not Vietnamese fish sauce. I just want the word fish sauce. Or I could go with a partial phrase match, meaning no modifications to this part of the phrase, but yes if it's Vietnamese fish sauce or fish sauce recipes, that's fine. Or I could go fish sauce broad match and then let Google sort of extrapolate out and add all sorts of things on there. Now, as of September of 2014, Google AdWords is making a change to their policy. All campaigns and keywords that you employ inside campaigns must use close variance. Essentially, they're removing the exact match and saying, "Hey, we don't think this power tool is useful, and that control is going to be lost to folks." Get the full story at The Moz Blog