Keywords are the gateways to your site and how people find you more often than not, so 
keyword research is extremely important. One aspect of keyword research which people get confused about when using their keyword tool of choice is the difference between broad match versus phrase match versus exact match; all of which give different results numbers you’ll notice when you do a search, so let me address each one individually with examples to explain it better.
Broad Match Vs Phrase Match Vs Exact Match
So let’s say we do a search for “guitar chord charts” as our example.
Broad Match – Search results 1700.
Broad match refers to any order of your keyword phrase. So with “guitar chord charts”, this can be:
“guitar chord charts”, “guitar charts chord”, “chord guitar charts”, “chord charts guitar”, “charts chord guitar”, or “charts guitar chord”.
It’s all getting lumped together which isn’t very helpful or representative of the number of people searching for our example “guitar chord charts”.
Phrase Match – Search results 800.
Phrase match is getting more specific and includes our phrase in the SAME ORDER as we searched, plus additional words on either end. So this could include:
“free guitar chord charts” or “guitar chord charts pictures”.
Exact Match – Search results 400.
Exact match is just that, the exact phrase “guitar chord charts” and nothing else in the phrase, just people who are searching for those three words in that order.
When choosing keywords for Adwords, you’ll want to use the exact match setting most of the time because you don’t want your ad being triggered by irrelevant keywords. Not only will this potentially result in untargeted clicks which is a waste of money, but this can offset your CTR which can raise your CPC.
When choosing keywords for your own site to target, it’s not as important to focus on exact match because if you do a post on “guitar chord charts” and you continue to build it up to the top of the SERPs for that phrase through SEO, you’ll eventually be ranking for permutations of that phrase and with other words attached to the search.
Another way to think of broad match versus phrase match versus exact match for SEO purposes is that your exact match search number is the traffic you can expect in the short term for targeting that keyword, then the phrase volume number will come next, and finally you can expect the largest number of search volume which is associated with the broad match to come in the long term after you’ve done a lot of optimization for that keyword.