What is Spring Boot?
Spring is a huge Java framework for back-end apps, and Spring Boot is the easy way to use it — almost no setup.
What you will learn
- Explain what Spring and Spring Boot are
- Say why Boot makes Spring beginner-friendly
- Know what a back-end app does
What is a back-end?
When you open an app, the part you see and tap is the front-end. Behind it sits the back-end — the program on a server that stores data, checks logins, and answers requests. Spring Boot is for building that back-end in Java.
A back-end usually talks to the world through an API (Application Programming Interface — a way for two programs to talk to each other). The front-end sends a request (like give me all products), and the back-end sends back data. You will build exactly these APIs in this course.
Spring vs Spring Boot
Spring is a very popular, very large Java framework. It is powerful, but plain Spring needs a lot of fiddly setup before you can run anything. That scared away beginners for years.
Spring Boot sits on top of Spring and removes almost all of that setup. It gives you sensible defaults, a built-in web server, and a single command to run your app. Spring is the engine; Spring Boot is the ready-to-drive car.
| Plain Spring | Spring Boot | |
|---|---|---|
| Setup | Lots of XML / config by hand | Almost none — smart defaults |
| Web server | You install and configure one | Built in (Tomcat) — just run |
| To start | Many steps | One main method |
| Good for beginners? | Hard | Yes — start here |
Why so many companies use it
- It is the standard way to build Java back-ends — huge job market.
- It makes REST APIs (the topic of Unit 2) very quick to write.
- It connects to databases with little code (Unit 3).
- It has security, testing and deployment built in.
Tip: You already know Java — classes, methods, objects. Spring Boot is just Java plus some helpful annotations (the @ labels). You will keep writing normal Java; Spring does the heavy lifting around it.
Watch out: Do not try to learn all of Spring at once — it is enormous. This course teaches the small, practical slice you actually need to build real APIs. Learn it one annotation at a time.
Q. What is the main reason to use Spring Boot instead of plain Spring?
✍️ Practice
- In your own words, write one sentence each for “front-end”, “back-end” and “API”.
- List three things a back-end might do for a shopping app.
🏠 Homework
- Find two well-known companies or apps that use Java/Spring on the back-end and note what kind of app each is.