Google Ads refers to Google Advertisement. Google Ads is the biggest advertisement company in the world. They sell advertisements trough 3 main channels:

• Google Search Engine
• Google YouTube
• 3th party Websites

If you want to promote your product with Google Ads, you have to create an account in Google Adwords.

If you want to earn money with selling advertisement space of Google Ads, you can create an account in Google Adsense.