Welcome to our SQL Basics in PostgreSQL course. In this course, you will get to know how to talk to databases.

What is a database exactly? To put it simply, it's a computer program which stores various data. There are quite a few database vendors, e.g., Oracle, MySQL, SQL Server, and many others but we'll focus on the PostgreSQL database. Chances are some of these names already sound familiar to you – after all, databases can be found literally everywhere!

There are various types of databases. In this course, we're going to focus on relational databases – they're a very frequent choice in the contemporary IT world.

The chief advantages of PostgreSQL are:

• It's open-source & free.
• It had a lot of features before any other database, and it still can offer a lot more.
• It has a plethora of extensions (such as PostGIS).

In the Code Editor you can see a query that does one thing: retrieves students' names and their graduation years but only for those who graduated in 2015. The result table is sorted by the birth year in descending order – it shows the youngest students first.

Don't worry if you don't understand the command yet; you'll learn how to write such commands yourself in this course.

Let's find out about how relational databases are organized.