Authentication - 401-advanced-javascript-jv/seattle-javascript-401d30 GitHub Wiki

Accessing secure information on the internet requires methods of keeping that information behind a wall that only people with correct credentials are able to get through. This is the basic idea behind authentication. A server knows who is allowed and will only provide information once a user has proven they're on the list.

Authentication is process of requesting identifying information from a user and verifying that information.

There are multiple ways of providing this, from basic authentication to third-party verification. Some are more secure than others. When designing an authentication system, think about how critical it is. More secure systems are more complex, take longer to operate, and are more difficult to implement, but provide better assurance of security. Less secure systems are easier to implement, less complex, and are quicker.