What Is a Database?

What are databases?

A database is a structured system for storing, managing, and retrieving data, enabling everything from simple recordkeeping to powering complex applications and services.

Key takeaways

Databases store and organize data, making it easy to retrieve, manage, and analyze information.
Certain types of databases are especially suited to handle unique data structures.
Database management systems (DBMSs) handle data storage to ensure efficiency and security.
Cloud databases and sharding are shaping how organizations scale performance.

What is a database used for?

To fully understand databases, it’s important to recognize how these systems go beyond simple recordkeeping—they lay the foundation for efficient data management, powerful analysis, and secure operations at scale. Databases are engineered to handle evolving needs, streamlining the way information is processed for organizations of all sizes.

Databases are used in nearly every digital experience, including powering websites and mobile apps, supporting CRM, inventory tracking, and financial reporting. They allow organizations to make data-driven decisions, automate workflows, and scale operations.

Key components

Databases can include:

Tables or collections that organize data into rows and columns or flexible formats.
Schemas that define the structure and rules for data.
Indexes that speed up data retrieval.
Database management systems (DBMSs) that control how data is stored, accessed, and secured.

What sets databases apart from other data storage methods—such as flat files or spreadsheets—is their ability to support concurrent access, enforce data consistency, and integrate with applications in real time. This makes them essential for modern computing environments, especially in cloud platforms where scalability, availability, and performance are critical.

DBMS: How databases work

A DBMS is the software layer that allows both employees and applications to interact with a database. It manages the storage, organization, retrieval, and protection of data.

The DBMS performs several critical functions:

Data storage—organizing data into structures, such as tables, documents, or key-value pairs.
Access control—managing permissions and authentication.
Backup and recovery—ensuring data durability and availability.
Performance optimization—indexing, caching, query planning, and database sharding to speed up operations.

Data retrieval and manipulation

Data operations in a database typically follow the CRUD model:

Create new records to the database.
Read through existing data using queries.
Update those existing records.
Delete data that’s no longer needed.

These operations are executed using query languages, such as structured query language (SQL) for relational databases or API calls for NoSQL systems. For example, the SQL query SELECT * FROM Customers WHERE Country = 'USA' retrieves all customer records from the U.S.
Modern DBMSs also support:

Joins that combine data from multiple tables.
Transactions that ensure data integrity across multiple operations.
Stored procedures to automate complex logic within the database.

In the cloud, these processes are further enhanced by scalability, high availability, and integration with analytics and AI services.

Types of databases

Relational databases

Relational databases (RDBMSs) store data in structured tables with rows and columns, using relationships between tables to organize information.

Best for: Structured data with clear relationships, such as customer records, financial transactions, or inventory systems.

Example: A retail company tracking orders, customers, and products across multiple locations.

SQL databases

A SQL database is a relational database that uses SQL to manage and query the data. All SQL databases are relational databases, but not all relational databases necessarily use SQL as their primary interface—though in practice, most do.

Best for: Managing structured data that fits neatly into tables with defined relationships.

Example: Banking, e-commerce, and inventory systems where accuracy and reliability are essential.

PostgreSQL

PostgreSQL is a powerful, open-source RDBMSs that uses SQL to manage and query data. It’s known for its reliability, scalability, and advanced features, making it suitable for a wide range of applications.

Best for: Supporting both traditional relational data and more complex data types, such as JavaScript object notation (JSON).

Example: A software-as-a-service company managing accounts, billing data, and application settings.

NoSQL databases

Non-relational (NoSQL) databases are designed for flexibility and scalability. They store data in formats, such as key-value pairs, documents, graphs, or wide-columns—ideal for unstructured or semi-structured data.

Best for: Rapidly changing data, large-scale web apps, real-time analytics, or hierarchical data.

Example: A social media platform storing account profiles, posts, and interactions in a document-based format.

Key-value databases

These are the simplest form of NoSQL databases, storing data as key-value pairs. They offer fast performance and are often used for caching or session management.

Best for: High-speed lookups, caching, and lightweight data storage.

Example: An e-commerce site caching product details for faster page loads.

Document databases

Document databases store data in JSON or extensible markup language (XML) formats, allowing nested values and flexible schemas.

Best for: Content management systems, user-generated data, and applications with evolving data models.

Example: A blogging platform storing articles, comments, and metadata.

Graph databases

Graph databases use nodes and edges to represent relationships, making them ideal for complex, interconnected data.

Best for: Social networks, recommendation engines, fraud detection.

Example: A travel app mapping connections between accounts, destinations, and preferences.

Time-series databases

These are optimized for storing and querying time-stamped data, such as metrics, logs, or sensor readings.

Best for: IoT applications, performance monitoring, financial data tracking.

Example: A smart home system logging temperature and energy usage over time.

Object-oriented databases

These databases store data as objects, similar to how it's represented in object-oriented programming languages.

Best for: Applications with complex data models and tight integration with code.

Example: A simulation tool modeling real-world entities such as vehicles or buildings.

Why databases matter

Databases are the backbone of modern digital systems. They store, organize, and manage data in ways that make it accessible, secure, and easy to act on, whether powering websites, mobile apps, enterprise platforms, or real-time analytics. With structured customer records and dynamic content feeds, databases empower businesses and developers to build smarter, faster, and more scalable solutions.

As database technology continues to evolve, so do their capabilities. Key trends shaping the future include public, private, and hybrid cloud architectures, distributed systems, real-time data processing, and AI-driven automation. These innovations are helping organizations handle growing data volumes, improve performance, and explore deeper insights—making databases more critical than ever.

Get started with Azure databases

Put your data to work with Azure. It offers a powerful suite of cloud-based database solutions designed for scalability, security, and performance. Whether you're building your first app or modernizing enterprise systems, Azure makes it easy to get started. Explore Azure databases today and bring out the full potential of your data.

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FAQ

A database is a structured system for storing and organizing data so it can be easily accessed, managed, and updated. It helps people and applications retrieve information efficiently and is essential for everything from websites and apps to enterprise systems.
Aside from storing and organizing data, databases help ensure data consistency, support decision-making, and allow for automation across systems—including websites, mobile apps, and enterprise platforms.
An example of a database is PostgreSQL, an open-source relational database system used to store and manage structured data. It's commonly used for web applications, financial systems, and data analytics due to its reliability, scalability, and support for complex queries.
Databases are used by a wide range of people and organizations—including developers, data analysts, businesses, governments, and schools. Anyone who needs to store, manage, or analyze data—such as customer info, financial records, or inventory—can benefit from using a database.
The most common type of database is the relational database, which organizes data into structured tables with rows and columns. It uses structured query language (SQL) to manage and query data, making it ideal for applications that require consistency, complex queries, and transactional integrity—such as banking systems, e-commerce platforms, and enterprise software. Examples include PostgreSQL, MySQL, and Microsoft SQL Server.