The most important component of a website is having users. Real humans who can contribute to the website. If Facebook had no users then it would just be adverts. If blogs had no users then it would just be the ramblings of an author.

But in order to have users and associate data to user accounts, we need a way to register them and allow them to sign back into their accounts at a later date.

This means they will be giving us some information that we have to keep secure. This is what authentication is all about, how to figure out if a user really is who they say they are. And that is the goal of today; Figure out how to register, login and logout users with email and password. So they can access their own private profile pages.

Also, we're going to allow users to download a top-secret Flask Programming Cheat Sheet. But only when they have registered and signed up to our website.

Here's a demo of what we'll create by the end of the day: