High traffic keywords are the search terms that get a lot of search hits. High CPC keywords are the keywords that get a lot of money form advertisers. There is a huge difference between these two types of keywords. Entertainment is high traffic niche, you can get a lot of traffic but the money you can make from ads on entertainment blogs isn't that high. On the other hand, topics like finance and business have high CPC, thus, pay well for ads. So, if you want to make money from your website, you need to target high CPC keywords.