CTR = click through rate. For example, if a banner ad is delivered 100 times (100 impressions) and receives one click, then the click-through rate for the advertisement would be 1%. CPC = cost per click.
Banned already? Nevertheless, I will answer, CTR (Click Through Rate)-> is the ratio between clicks and impressions. It's highly dependent on the banner relevancy for your site, and the banner itself. So for example if the banner is appealing to the user and has a clear Call 2 Action, it will have a higher CTR CPC (Cost Per Click) represents the amount you are earning per each click on the ad(banner). It depends on the CPC platform you're using. For example adsense can pay you anywhere between $0.01 and $3(maybe even more) for each click
CTR means Click Through Rate.. Means, How many clicks you receive per impressions.. 100 impressions on your page and one user clicks on your ad,.. means CTR = 1% I hope it is clear to you now !!