# Databases
Before we dive deep into SQL, let's quickly define what a database is.
The definition of databases from Wikipedia is:
> A database is an organized collection of data, generally stored and accessed electronically from a computer system.
In other words, a database is a collection of data stored and structured in different database tables.
## Tables and columns
You've most likely worked with spreadsheet systems like Excel or Google Sheets. At the very basic, database tables are quite similar to spreadsheets.
Each table has different **columns** which could contain different types of data.
For example, if you have a todo list app, you would have a database, and in your database, you would have different tables storing different information like:
* Users - In the users table, you would have some data for your users like: `username`, `name`, and `active`, for example.
* Tasks - The tasks table would store all of the tasks that you are planning to do. The columns of the tasks table would be for example, `task_name`, `status`, `due_date` and `priority`.
The Users table will look like this:
```
+----+----------+---------------+--------+
| id | username | name | active |
+----+----------+---------------+--------+
| 1 | bobby | Bobby Iliev | true |
| 2 | grisi | Greisi I. | true |
| 3 | devdojo | Dev Dojo | false |
+----+----------+---------------+--------+
```
Rundown of the table structure:
* We have 4 columns: `id`, `username`, `name` and `active`.
* We also have 3 entries/users.
* The `id` column is a unique identifier of each user and is auto-incremented.
In the next chapter, we will learn how to install MySQL and create our first database.
Before we dive deep into SQL, let's quickly define what a database is.
The definition of databases from Wikipedia is:
> A database is an organized collection of data, generally stored and accessed electronically from a computer system.
In other words, a database is a collection of data stored and structured in different database tables.
## Tables and columns
You've most likely worked with spreadsheet systems like Excel or Google Sheets. At the very basic, database tables are quite similar to spreadsheets.
Each table has different **columns** which could contain different types of data.
For example, if you have a todo list app, you would have a database, and in your database, you would have different tables storing different information like:
* Users - In the users table, you would have some data for your users like: `username`, `name`, and `active`, for example.
* Tasks - The tasks table would store all of the tasks that you are planning to do. The columns of the tasks table would be for example, `task_name`, `status`, `due_date` and `priority`.
The Users table will look like this:
```
+----+----------+---------------+--------+
| id | username | name | active |
+----+----------+---------------+--------+
| 1 | bobby | Bobby Iliev | true |
| 2 | grisi | Greisi I. | true |
| 3 | devdojo | Dev Dojo | false |
+----+----------+---------------+--------+
```
Rundown of the table structure:
* We have 4 columns: `id`, `username`, `name` and `active`.
* We also have 3 entries/users.
* The `id` column is a unique identifier of each user and is auto-incremented.
In the next chapter, we will learn how to install MySQL and create our first database.