Welcome to lesson three. This’ll be databases. Databases are how you actually store all those information that we’ve been collecting from users. This is basically the final piece that’ll allow us to build fully functional web applications, and your homework for this lesson ought to be actually build the first version of your blog. So. Databases are actually quite complex. We can spend a lot of time talking about them. You can actually get a Ph.D in databases if you want. But, in this lesson, we have about an hour, so we’re going to divide it into two parts. The first part of this lesson will talk about SQL and kind of basic database technologies, a lot of things you’ll probably encounter outside of this course. And then, in the second part of this lesson, we will talk about Google App Engine’s data store which abstracts away a lot of the headaches of installing a database and getting it setup. It’s actually the reason we decided to use App Engine for this course, it was the ease of getting started with databases, so let’s dive right in.