When it comes to a page and not an individual profile, when a user is interested in a particular page (business, public figure, band, organization) and likes it, he automatically follows the page.
Now at some point, if the user wishes not to see posts of the page anymore, in that case one can ‘unfollow’ the page but still continues to ‘like’ the page. Hence there could be a discrepancy between the number of likes and follows for pages.