## Basic concepts
Databases are widely used, but one database model cannot meet the varying requirements of different projects, servers, etc. There are various types of databases and database management systems.

- **Database (DB)** is a storage of information.

- **Database Management System (DBMS)** is a set of tools used to manage and operate a database. It helps users control the data and database structure, and provides an interface for it.

There are two main database models: **relational** and **non-relational** databases.

**Non-relational databases** are divided into many different types, such as document data stores, column-oriented databases, key-value stores, document stores, and graph databases.



Also, there are multi-model database management systems like **Oracle Database**. 

In this section, you will become familiar with both relational and non-relational databases and learn how to create diagrams to represent database structures.

This section delves deeper into the topic of relational databases and provides a comprehensive overview of the key theoretical concepts. Topics covered include foreign keys, the different ON DELETE options, and the various types of relationships.

It's time to learn how to construct databases, with a focus on ensuring a well-structured database for optimal functionality. In this section, you will familiarize yourself with the key principles for building a database for ease of use.

Basic concepts

The most popular database management systems

What models are databases divided into?

Select a few correct answers

Choose relational databases:

Select a few correct answers

Choose non-relational databases:

Select a few correct answers

Relational	Non-relational
- MySQL	- MongoDB
- PostgreSQL	- Redis