Display ads that in a Digital Marketing Course can be simplified as whenever we scroll through any of the website we tend to check on ads that appear thus, once you put those ads on your website, you encourage users to click on those ads and purchase a few things thus you earn a part of that purchase.
It is one of the Google service and in this the advertisement can be done in any mode like it can be a picture or a video etc. they are managed in such a way that they automatically appear in front of whatever you are doing. Sometimes it, ok but sometimes people get angry or irritated but do you know that whenever we click in any of the ads, it gets paid.
When you put your ad on it you get paid according to the click and how many people have watched your videos.
Think of that you have a website of yours and you are showing four ads per day on your page so you will get [paid according to it this is how Google Ad sense work.