AdWords is a service or system owned by Google. There are several other related services too. This service allows people to make money by putting ads on their own websites. AdWords and the other services require these people and websites to generate a lot of views by others. If a website only has a few views, then the AdWords would most likely not put ads on this site.
When the website meets the criteria, then the website owner can set up an account. Once the account is set up, then the account will need information from the website owner. Some of the settings would include the email address and the billing information about the website owner. This is needed so that advertisers know where to send the money.