What is Inversion of Control (IoC) and how does the Spring IoC Container work? इनवर्ज़न ऑफ़ कंट्रोल (IoC) क्या है और स्प्रिंग IoC कंटेनर कैसे काम करता है?

Inversion of Control is the broader principle behind DI: control over object creation and wiring is inverted from the application code to a framework/container. Instead of a class controlling when and how its dependencies are constructed, the Spring IoC Container owns that responsibility.

The container, represented by ApplicationContext, reads bean definitions (from annotations, Java config, or XML), instantiates beans, resolves their dependencies, and manages their full lifecycle. This is why Spring applications are described as having their control "inverted" — the framework calls your code, not the other way around.

ApplicationContext context = SpringApplication.run(DemoApplication.class, args);
OrderService orderService = context.getBean(OrderService.class);