What is Spring used for?

Spring provides an overall framework for enterprise-level applications to develop robust and scalable applications using Java. It makes the development of web applications, microservices, and RESTful APIs painless, with the ability to focus on business logic instead of boilerplate code. Core features include dependency injection, aspect-oriented programming, and easy integration with various databases and messaging services. It allows the developer to decide which components to use due to its modular nature; hence, Spring is flexible and can adapt to a wide range of application architectures and use cases.