Facebook distinguishes between an ad click and an actual page view as follows: If someone clicks a link on your ad, but then closes out your page before it loads, that counts as a link click only, but not a landing page view. So, only if the users wait for the page to load and actually visit your landing page, a page view is measured in addition to the ad click.

In your Horizon dashboard, ad clicks are taken into consideration for the Cost per Click KPI, while Cost per Visit is calculated based on users visiting your page.