What Is a Database?

Written by Coursera Staff • Updated on

Learn about the basics of databases, how they work, and their role in storing and managing information efficiently.

[Featured image] A data analyst works with a database on a desktop computer in an office with big windows.

What is a database?

A database is an organized collection of information that can be searched, sorted, and updated. This data is often stored electronically in a computer system called a database management system (DBMS). Databases typically organize data in rows and columns for easy processing and retrieval. Oftentimes, you’ll need to use a programming language, such as structured query language (SQL), to interact with your database.

Databases are similar to spreadsheets, but there are several key differences. In general, databases are much larger than spreadsheets and so can store more data, and they allow for multiple users to access data at the same time. For these reasons, people who work with data, such as data analysts and data scientists, often work with databases rather than spreadsheets.

Read more: Relational vs. Non-relational Database: The Difference Explained

What is SQL (Structured Query Language)?

SQL is a programming language used on almost all relational databases to query and manipulate data. It is still widely used to day for querying databases to access the right data needed, but new languages have begun to appear in this space.

Read more: What Does SQL Stand For?


Types of databases

There are several types of databases, including:

  • Relational database: A relational database stores and allows access to data. These types of databases are considered "relational" because the items within them have pre-determined relationships with one another. Data is stored in tables, which are connected by unique IDs or "keys." To access specific information, users enter the key to access the data that has been programmed to be related to that key.

  • NoSQL database (or nonrelational database): A non-relational database (also known as a NoSQL database) stores data in whatever format is best for the type of data being stored. They tend do contain unstructured data, or data that is less defined, like emails, videos, images, and documents. They are called NoSQL because they don't use SQL.

  • Distributed database: A distributed database stores data in several different physical locations. Processing data in this type of database is spread out. Distributed databases can be homogenous and have the same hardware in each physical location and run the same systems and applications, or they can be heterogenous and have different operating systems in each location.

  • Object-oriented database: An object-oriented database focuses on organizing objects, rather than actions or logic. Instead of being assigned an alphanumeric value, it would remain its original object type.

  • Graph database: A graph database is a type of NoSQL database. It stores, queries, and maps relationships according to the graph theory. Graph databases are used to analyze interactions and connections. They consist of nodes and edges, and use a declarative programming language called SPARQL.

  • Cloud database: A cloud database is built in a cloud to optimize for a virtual work setting and distribution. Organizations tend to be charged based on the amount of storage or bandwidth they use.

  • Open-source database: These databases are open-source, meaning anyone can contribute or edit the source code. They can be SQL or NoSQL.

  • Data warehouse: Data warehouses are central repositories for data. A data warehouse is designed to be swift, so users can query and analyze data quickly.

Each database type is characterized by specific storage and retrieval practices, data types, job functions, and use cases.

Learn more about databases from experts at Google:

Components of a database

The different types of databases vary in terms of data structure, data types, and schema. Database schema is a blueprint that outlines a database's architecture, describing how the data inside is organized and how different elements (such as foreign and primary keys, fields, etc.) relate to each other.

All types of databases have the following five components:

  1. Hardware: Database hardware is the physical device that the software runs on, so that users can query and pull data from it. Hardware examples include computers, hard drives, and servers.

  2. Software: From the hardware, database software allows users to manipulate the database for their needs. A database management system (DBMS) manages several databases.

  3. Data: The data itself is a core component of the database. It is the raw information that is stored on the database and managed by database administrators. Users can then access the data to derive meaning for specific teams and projects.

  4. Procedures: Procedures are the rules that determine how the database runs and handles data.

  5. Data access language: Data access languages are programming languages (such as SQL) that are used to control and manage the database. They must align with the DBMS and work in sync.

Related terms

Learn more about data analysis

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