For the first time ever, Google is targeting children under 13 for account creation. The new "Google Family Link" app allows parents to make special Google accounts for kids under 13, which can be monitored and locked down. Right now, the program is in a US-only, invite-only "early access" beta, and the child's device has the hefty requirement of running Android 7.0 Nougat and up.
In the US, the Children's Online Privacy Protection Act (COPPA) restricts the collection of data on children under 13, requiring parental notification and consent. Previously Google complied with this law by banning kids under 13 from making an account. Google has created some kid-focused products in the past, namely YouTube Kids, but that app did not have a login feature—a bummer for anyone who wanted customization or their ad-free YouTube Red subscription to work.
from Parents can now create Google accounts for their kids with Google Family Link