According to Apache Camel site (http://camel.apache.org/): Apache Camel is a powerful open source integration framework based on known Enterprise Integration Patterns with powerful Bean Integration.

But before jumping on to Camel, the understanding of integration patterns is must which is defined by Gregor Hohpe in his book Enterprise Integration Patterns. The same is briefly described in his website (http://www.eaipatterns.com/index.html). Also very brief summary of the same is mentioned by developers of Camel at FuseSource known as EIP Flashcards.

Now if you know integration patterns Camel is just the implementation of as many of these as known. The most basic example of Camel is written by Jonathan Anstey @ http://java.dzone.com/articles/open-source-integration-apache. This example describes Rider Auto Parts web store example and how integration patterns help in integration of distinct applications through Camel. There is a presentation on Camel known as Introduction to Camel Webinar Slides by FuseSource which is helpful.

Now that you know Camel you know it provides:

  1. Implementations of various EIPs.
  2. Large number of Transports.
  3. DSLs to connect EIPs to Transports.