Your keywords is one of the basic building blocks in order to improve your search engine ranking but then knowing your competitors targeted keyword would certainly give you an advantage....
this is a basic procedure that we normally forget... so here is how you do it.
1.) Go to your competitors website using any browsers but i would prefer google chrome.
2.) go to the menu bar of your browser and look for tools.
3.) once you are in the tools option select view page source.
4.) Now a lot of codes would appear just try and look for a code that states /><meta name="Keywords" content
5.) Bingo! All the words after the /><meta name="Keywords" content are your competitors keywords.