When you sign in to your Android device with your Google Account, you can sync up your data on one device. This sync includes your email, contacts, calendar events, and other data associated with your Google Account.
You can even manage how apps connected to your Google Account are synced on your mobile device.
When using YouTube Kids,we recommend that you create a restricted profile for your child if you want to use signed in features. You can then choose which apps, features, and content are available for that restricted profile on that device. For example, you can create a restricted profile to prevent a family member from using your tablet to view mature content.