Google Ads glossary
A landing page is the page on your site that a person reaches after clicking your ad.
Every ad has a final URL: the address of its landing page. It must be on the same domain as the URL shown in the ad.
Google rates the experience on that page: how useful and relevant the information is, how easy the site is to navigate, how many links the page has, and whether it matches what the ad promised. It is one of the three components of Quality Score.
You pay for the click before the person sees your page. If the page answers neither the search nor the ad, you paid for a visitor who leaves.
Sending a buying keyword to a blog post or to the homepage wastes the intent. Each ad group should lead to the page that answers its searches precisely.
For the search “car insurance quote for new drivers”, the right landing page is a quote form built for new drivers. The insurer’s homepage makes the person hunt for what they want.
Free tool: UTM builder
The UTM builder adds to your landing page URL the parameters that tell you where each click came from, with a tracking template ready for Google Ads.
Official source: Google Ads Help: landing page