A Google Ads field for the tracking address called when an ad is clicked, with {lpurl} standing in for the final URL.
The tracking template is where an advertiser puts the tracking it wants called on a click, separate from the final URL. It can be set for the account, a campaign, an ad group, an ad, a keyword and more. A typical template is a tracker's address with the final URL passed in: https://trk.network.example/c?pid=41207&url={lpurl}, where {lpurl} is a ValueTrack parameter Google replaces with the final URL.
Under parallel tracking the template loads in the background while the shopper goes straight to the final URL. Google's Destination requirements ask that the template lead to the same content as the final URL.
That's the mechanism behind an affiliate's ad that shows your address: the final URL is your site, so the ad shows your domain, and the template carries the network's link, so a sale can be credited to the publisher. Nothing in the ad shows the template. From outside, you see its effects: a gclid beside parameters you didn't set, sales credited to a publisher soon after a search for your name, and an advertiser in the Ads Transparency Center you can't match to your own accounts.
Google's own help and policy pages first.