Google Adsense

Google AdSense is a free, simple way for website publishers of all sizes to earn money by displaying targeted Google ads on their websites. You can also use AdSense to provide Google search for your site’s visitors, while earning money by displaying Google ads on your search results pages.
Welcome to Google AdSense
Learn the basics of AdSense in this overview designed for publishers who’ve just joined the program.
How does it work?
1. You make your ad spaces available

You specify where you want ads to appear
You choose what types of ads can compete for those spaces

2. The highest paying ads appear on your site

Advertisers bid on your ad inventory in a real-time auction
We always show the highest paying ad

3. You get paid

Google handles billing advertisers and ad networks
You get paid through our reliable payment options

More features

Review and block competitors’ or unwanted ads
Choose from a wide variety of ad formats
Identify opportunities with performance reports and Google Analytics integration

If you have a website that complies with our program policies and eligibility criteria, we encourage you to give a try to AdSense. Learn more about publishers who are seeing success with AdSense in our Success stories.

(source: https://support.google.com/adsense/answer/9712?hl=en)