Lazy Load requires MRA (Multi Request Architecture)
In this tab, lazy load settings can be specified for each publisher.
Fetch margin (in percentage of viewport) - how fast (how early before being in viewport) an ad should be fetched to an ad slot (ad request should be made)
Render margin (in percentage of viewport) - how fast (how early before being in viewport) an ad should be displayed (creative should be displayed)
Mobile scaling - multiplier of Render and Fetch margins for mobile devices
A very good simulation of the following drawings: https://developers.google.com/publisher-tag/samples/lazy-loading?hl=de#typescript
SRA (Single Request Architecture)
The settings for fetch margin are completely ignored
MRA (Multi Request Architecture) - required if Lazy Load is active
