Using your Amazon account to Sign-In to an external application
Why should I Sign-In with my Amazon Account on a third-party site?
You will have one less password to remember when you use your existing Amazon user name and password to Sign-In to a third-party site using Login with Amazon. You will also be Signed-In to Amazon Payments so that you can access your payment and shipping information to securely complete a purchase. If you do not have an Amazon Payments account, we will create one for you using the information we have from your Amazon account.
What information is shared with sites that use Login with Amazon?
What if I no longer want to Sign-In to the third-party site with my Amazon Account?