There are many definitions of a database available online. A good one can be found at:
https://en.wikipedia.org/wiki/Database
But why does hosting include a database? Basically, because databases make websites far more interesting. Today, very few websites do not use a database to display information. The very text you are reading right now is stored in a database.
Databases are one of the fundamental building blocks of the web today. They will be essential for your website too. For example, if you use any of the applications you can automatically install on your hosting through Softaculous, you will be using databases.
But do not worry. You hardly need to know what a database is to take full advantage of one.
Our system makes everything very simple and intuitive to manage. And if you have any questions, just contact us.