The Core package is the most fundamental part of the framework and provides the IoC and Dependency Injection features.
The Context package build on the solid base provided by the Core package: it provides a way to access objects in a framework-style manner in a fashion somewhat reminiscent of a JNDI-registry.
The DAO package provides a JDBC-abstraction layer that removes the need to do tedious JDBC coding and parsing of database-vendor specific error codes.
The ORM package provides integration layers for popular object-relational mapping APIs, including JPA, JDO, Hibernate, and iBatis.
Spring's AOP package provides an AOP Alliance-compliant aspect-oriented programming implementation allowing you to define, for example, method-interceptors and pointcuts to cleanly decouple code implementing functionality that should logically speaking be separated.
Spring's Web package provides basic web-oriented integration features, such as multipart file-upload functionality, the initialization of the IoC container using servlet listeners and a web-oriented application context.
Spring's MVC package provides a Model-View-Controller (MVC) implementation for web-applications. Spring's MVC framework is not just any old implementation, it provides a clean separation between domain model code and web forms, and allows you to use all the other features of the Spring Framework.
