Summary  
This chapter introduces the caching concept, explaining how Redis stores and retrieves data on cache hits and misses to speed up subsequent data access.  

General domain of usage  
Performance optimization in web applications

We'll explore how **Redis** is used for **caching** and why it’s such a popular choice. For testing and development, we'll use **Spring Boot** as the server framework.

To follow along with the examples in this section, you should have a **basic understanding** of **Spring Boot** and **Java**.

Note

1. When a **user** sends a **request**, the **server** first checks if the required **data** is in the **cache** (**Redis**);

2. If the **data** is in the cache (**cache hit**), it is immediately **returned** to the user;

3. If the data is not in the cache (**cache miss**), the **server retrieves** it from the **database**;

4. The retrieved data is then **stored** in the **cache** for **future use**;
5. Finally, the data is **returned** to the user.

**Spring** is just one example of how **Redis** can be used. Developers building backends with other **languages** or **technologies** can also integrate **Redis** seamlessly into their projects.

# What’s next?

**In this section**, we'll build an application integrated with **Redis** to demonstrate how **caching** works. We'll create a simple **REST API** and **evaluate** its performance with **caching enabled**.

**Caching** not only improves **response times** for users but also reduces **database load**, making the application more **scalable**.

This course will introduce you to the fundamentals of Redis and its use in real-world applications. We'll cover key Redis commands, data types, key expiration and transactions, as well as how to integrate Redis with Spring for efficient data caching.

This section provides an introduction to Redis, highlighting its core features and common use cases. You’ll learn how to install Redis on different platforms, including Windows and macOS, and get familiar with the basics of connecting to and starting the Redis server.

Here, we explore the essential Redis commands for managing and manipulating data effectively. You'll learn how to set, retrieve, increment, and delete data using commands like SET, GET, EXISTS, INCR, DECR, and tackle practical tasks to apply these concepts in real-world scenarios.

Here, you will learn about key Redis data types, including Lists, Sets, Sorted Sets, and Hashes. You will explore their functionality and practical applications through focused exercises designed to reinforce your understanding of each data type.

You'll explore advanced features of Redis, including managing key lifecycles, executing transactions, and leveraging the Pub/Sub messaging system. Additionally, you'll learn essential security practices to safeguard your Redis environment against unauthorized access.

This section introduces the fundamentals of caching and demonstrates how to configure Redis as a cache in a Spring application. It covers key caching annotations and practical examples of caching queries in web applications, concluding with a summary of the main concepts.

Introduction to Caching

How does caching work?

What’s next?