What is the difference between a 403 Forbidden error and a 401 Unauthorized error on a Chromebook?

A 403 Forbidden error means the server understands your request but refuses to authorize it, even if you provide credentials. A 401 Unauthorized error indicates that authentication is required to access the resource, and the server hasn't received valid credentials. In other words, a 401 error means you need to log in, while a 403 error means even if you log in, you still won't be granted access.