Spring From Scratch: Part 1
What Is Spring Boot and Why Does Half the Java World Use It?
By Steve Armstrong | Senior Software Engineer
I worked at Infosys on India’s first GST e-invoicing system. Spring Boot was the backbone of that backend. Millions of invoices, strict government compliance requirements, zero tolerance for downtime. It held up fine. That’s more or less when I stopped questioning whether this framework was worth learning.
This series is for people who want to actually understand Spring Boot, not just get it running and move on.
Spring Framework is not Spring Boot
This trips up a lot of beginners, so let’s get it out of the way first.
Spring Framework is a toolkit for building Java applications. It has been around since 2003 and is modular by design. You use what you need and ignore the rest.
The main modules:
Web — handles incoming HTTP requests, processes them, returns a response (HTML for a browser, JSON for an API)
Data — abstracts away the repetitive parts of working with databases, whether that’s SQL or something in-memory
AOP (Aspect-Oriented Programming) — lets you attach cross-cutting concerns like logging and security to your application without scattering that logic everywhere
Core — dependency injection and object lifecycle management. This is the thing that makes Spring, Spring.
Test — utilities for testing Spring components
Each module has a specific job. That’s the design philosophy and it works.
Spring Boot is a layer that sits on top of Spring Framework. It exists because setting up a raw Spring project involved a tedious amount of configuration that was almost identical every single time. Someone eventually decided that was silly, and Spring Boot was the result.
It gives you an embedded server, pre-wired dependencies, and a project structure that works out of the box. You spend less time on setup and more time on the actual problem.
Spring Framework gives you the parts. Spring Boot gives you the parts already assembled.
The Ecosystem
Spring Boot is one project in a larger family. Worth knowing what else is out there:
Spring Boot — removes setup friction. Your starting point.
Spring Framework — the core toolkit. Everything else builds on this.
Spring Data — cleaner database access
Spring Security — authentication and authorization
Spring Batch — large-scale batch processing
Spring Integration — messaging and system-to-system communication
Spring Cloud — microservices and distributed systems
You do not need most of this right now. It is just useful to have a mental map so you know what to reach for later.
What This Series Covers
We are going to build a backend store application from the ground up. Each part introduces one concept and builds on the previous one. No jumping ahead.
Part 1 (this one) — What Spring and Spring Boot are, and how they relate
Part 2 — Project setup and understanding what every file actually does
Part 3 — Your first REST API endpoint
Part 4 — Database access with Spring Data
Part 5 — Validation, error handling, and not embarrassing yourself with your API design
Part 6 — Security with Spring Security
More parts after that depending on where the series goes.
Who This Is For
You know basic Java. You have heard of Spring but the official documentation made your eyes glaze over. You want to understand the why, not just copy code that works for reasons you cannot explain.
If that is not you, this probably is not for you.
Part 2 covers project setup. See you there.
Steve