There are 5 main types of keywords you should be focusing on when doing your keyword research for PPC.
Generic Keywords - Terms and phrases specifically related to what you offer.
Brand Keywords - Your brand name and phrases that include your brand name.
Commercial Keywords - Terms a user might be typing when searching for a product you offer.
Competitor Keywords - Specific names of competitors that people in the market may be searching for.
Long-Tail Keywords - Longer more specific phrases that have low competition & cost.