Summary  
This chapter introduces the concepts of a database versus a database management system, outlines the difference between relational and non-relational database models, and categorizes popular DBMS types.  

General domain of usage  
Data storage and management in applications.

To analyze data with SQL effectively, you need to understand how the database works, including its structure, relationships, and how queries are processed. This knowledge will help you retrieve, manipulate, and interpret data accurately.

Note

## Basic Concepts
Databases are ubiquitous, but no single database model can cater to the diverse needs of various projects and servers. There's a spectrum of database types and database management systems.

- **Database (DB)** is a repository of information;

- **Database Management System (DBMS)** offers a suite of tools to manage and interact with a database. It allows users to oversee the data, structure the database, and provides an interface for these operations.

Primarily, there are two database models: **relational** and **non-relational**. Additionally, there are multi-model database management systems, such as **Oracle Database**.

**Non-relational databases** encompass a variety of types, including document data stores, column-oriented databases, key-value stores, and graph databases.

A focused introduction to relational databases for beginners. This course covers the essential concepts: how relational databases differ from non-relational ones, the entity-relationship model, types of relationships, primary and foreign keys, and the basics of normalization. Learners will gain a solid foundation in how data is organized and structured in relational database systems, preparing them for practical SQL and further database studies.

Introduction

Basic Concepts

The most popular databases

1. What models are databases divided into?

2. Choose relational databases:

3. Choose non-relational databases: