When creating a new Report you have the option of choosing between "Existing Content" and "New Content":
"Existing Content" should be used when you've already built the page that you're trying to rank. CanIRank will evaluate the page as it currently is, and give you recommendations for how it can be made more competitive.
"New Content" should be used when you're considering adding a new page and trying to figure out which keyword to target. Enter the URL of a page similar in importance and hierarchy to the one that you're trying to rank. For example, if you're trying to choose a keyword for a new blog post, choose "New Content" and enter the URLs of a few typical blog posts from your site (e.g., one popular blog post, one average blog post, and one weak blog post). CanIRank will evaluate the competitiveness of each page as if it were targeting that keyword. In doing so we make the assumption that you'll do a good job targeting the keyword with on-page optimization techniques. Don't worry if that doesn't mean anything to you; in the Action Plan we'll provide instructions.
New Content report types can be a great time-saver: by spending a bit more time upfront to choose the right keywords to target, you can save a ton of time getting those keywords to rank (and very high-scoring keywords, the "low-hanging fruit" of the SEO world, sometimes rank on page 1 shortly after you publish your post without any link-building or promotional efforts at all).
To see how "New Content" Reports fit into your overall SEO keyword research process, check out this video: