Spring is initial released by INTERFACE21 and now it removed as SpringSouce.org
Spring is a modular framework.
Spring framework can be used real time application.
Spring framework is non-invasive that means there is no need to extend or implement their class from any predefined class or interface given by Spring API.
Spring is light weight framework because of its POJO model
Spring Framework made J2EE application development very easy.
POJO is usually used to describe a class that doesn't need to be a subclass of anything, or implement specific interfaces, or follow a specific pattern. POJO = Plain Old Java Object. It has properties, getters and setters for respective properties.
Spring framework is simple, portable and non-invasive.
It is easy to execute spring application, because for testing spring application, server is not mandatory. Spring has it’s own container to run the applications
In spring objects are loosely coupled which is the core concept of spring framework. Later on we will see about loose coupling concept and it is advantageous from tight coupling