Update lazy load audit docs for clarity. Closes #287.

PiperOrigin-RevId: 450796886

docs/audits/ads-in-viewport.md

@@ -1,20 +1,26 @@
-# Avoid loading ads until they are nearly on-screen
+# Lazily load ads below the fold
 
 ## Overview
 
-This audit ensures that no more than three ads are loaded outside the viewport.
-Ads outside of the viewport are less likely to be seen by users, so loading an
-excessive number of them can lower viewability rates and decrease page
-performance.
+Key Term: "below the fold" refers to the area of the page outside of the initial
+viewport.
+
+This audit checks that no more than three ads are initially loaded below the
+fold. The area below the fold only becomes visible after a user scrolls down.
+Ads in this area are less likely to be seen by users, so loading an excessive
+number of them can lower
+[viewability rates](https://support.google.com/admanager/answer/4524488) and
+decrease page performance.
 
 ## Recommendations
 
-Defer loading ads outside of the viewport until they are nearly on-screen. See
-the
-[Google Publisher Tag Lazy Loading API](https://developers.google.com/publisher-tag/reference#googletag.PubAdsService_enableLazyLoad)
-for an example.
+Lazily load ads that are positioned below the fold. Lazy loading is a technique
+that prevents ads outside of the viewport from being requested and rendered
+until they are close to being scrolled into view. See the
+[GPT lazy loading sample](https://developers.google.com/publisher-tag/samples/lazy-loading)
+for an example implementation.
 
 ## More information
 
-[GPT Reference](https://developers.google.com/publisher-tag/reference)
+[GPT lazy loading API](https://developers.google.com/publisher-tag/reference#googletag.PubAdsService_enableLazyLoad)  
 [Viewability best practices](https://support.google.com/admanager/answer/6199883)