Hello guys, if you have been doing Java development then you would have definitely come across both Spring and Spring Boot framework These two Java frameworks have taken the software development world by storm and have become the go-to tools for building all kinds of applications. But what exactly are Spring and Spring Boot, and how do they differ from one another? This is one of the common questions which many Java programmer ask, particularly those who are starting with software development or new to Java world. In the past, I have shared several Spring and Spring boot articles, courses, books, projects, and interview questions but in this article, I am going to answer what exactly is Spring and Spring Boot and what is the difference between them? This will also help you to decide when to use Spring Framework or Spring Boot for Java application development. What are Spring and Spring Boot in Java?First, let's define what we're talking about. Spring is a framework for building Java applications. It provides a comprehensive set of features for building everything from small, simple applications to large, complex ones. Spring is designed to make it easy for developers to create scalable, maintainable, and testable applications. Spring Boot, on the other hand, is a subproject of Spring that focuses on making it super easy to create new, standalone applications with minimal setup and configuration. It's essentially a way to bootstrap a Spring application and get up and running quickly. So, if Spring is a comprehensive toolkit for building Java applications, Spring Boot is like a power drill that makes it faster and easier to get things done. But let's not get ahead of ourselves - there's a lot more to both of these frameworks than just that! One of the things that set Spring apart is its focus on the Inversion of control (IoC). This means that instead of your code calling directly into other objects or libraries, those objects and libraries are "injected" into your code as needed. This makes it easier to write flexible, reusable code and to change the behavior of your application without modifying the code itself. Spring also has a ton of other features that make it really useful for building applications. It has a powerful dependency injection framework, which makes it easy to manage the relationships between different objects in your application. It also has a robust data access framework that makes it easy to connect to databases and other data sources. And it has a whole host of other features, like support for web applications, security, and messaging, just to name a few. Spring Boot takes all of these features and packages them up in a way that makes it super easy to get started building a new application. Instead of spending hours or even days configuring all the different pieces of a Spring application, you can use Spring Boot to set up a basic application in just a few minutes. Spring Boot also has a number of "starter" dependencies that you can use to quickly add common functionality to your application. For example, if you want to build a web application, you can include the "spring-boot-starter-web" dependency and you'll get all the libraries you need to build a web application, including a web server and support for common web technologies like REST and JSON. Differences Between Spring and Spring Boot in Java App development One of the biggest differences between Spring and Spring Boot is that Spring Boot is opinionated. This means that it makes certain assumptions about how you want to build your application and provides a lot of default configurations based on those assumptions. This can be really helpful if you're just getting started with Spring and don't want to spend a lot of time configuring things. However, it can also be a little inflexible if you want to do things differently than the way Spring Boot expects. Another key difference between Spring and Spring Boot is that Spring is a framework, while Spring Boot is a framework and an application. This means that you can use Spring to build just about any kind of application, from a simple command-line tool to a complex, distributed system. Spring Boot, on the other hand, is specifically designed for building standalone applications, usually web-based ones. So why would you choose one over the other? It really depends on your needs. If you're building a simple, standalone application and you just want to get up and running quickly, Spring Boot is probably the way to go. It has a lot of default configuration and "starter" dependencies that make it easy to add common functionality to your application without a lot of setups. However, if you're building a more complex application or you need more control over the configuration of your application, Spring might be a better choice. It has a lot more advanced features and is more flexible than Spring Boot, so you can customize it to fit your specific needs. One other thing to consider is that Spring Boot is built on top of Spring, so if you're already familiar with Spring, you'll find it easier to use Spring Boot. On the other hand, if you're new to both frameworks, you might want to start with Spring Boot, as it's generally easier to get started with. Now that you know the basics of Spring and Spring Boot, you might be wondering how to get started using them. Fortunately, both frameworks have excellent documentation and there are plenty of tutorials and examples available online. You can also find a ton of third-party libraries and integrations that work with both frameworks, so you can easily add additional functionality to your application. So there you have it - a crash course in Spring and Spring Boot. Whether you're building a simple application or a complex, distributed system, these frameworks have you covered. Just remember: Spring is a comprehensive framework for building Java applications, while Spring Boot is a tool for quickly setting up and running a basic Spring application. So, to sum up: Spring is a comprehensive framework for building Java applications, while Spring Boot is a tool that makes it faster and easier to get started with Spring. Spring has a lot of advanced features for building complex applications, while Spring Boot is focused on making it easy to set up and run a basic Spring application. Hopefully, that clears things up a bit! Spring and Spring Boot are powerful tools that can make it much easier to build high-quality Java applications. Whether you're a seasoned Java developer or just getting started, they're definitely worth checking Other Spring and Hibernate Articles and Interview Questions you may like Difference between First and Second level cache in Hibernate? (answer) Difference between Hibernate, JPA, and MyBaits (answer) Top 5 Courses to learn Hibernate and JPA (Courses) Difference between Spring Boot and Spring Cloud? (answer) Difference between save() and persist() in Hibernate? (save vs persist) 10 Hibernate Questions from Java Interviews (list) 10 Free Courses to learn Spring Framework (Free courses) The Complete Java Developer RoadMap (guide) Why Hibernate Entity class should not be final in Java? 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