Executor , ExecutorService Interface and Thread pools

I was curious about the servlet specification 3.0 and wanted to read some article in order to get an understanding about it. Here is an overview which i prepared after some reading. I read more about Asynchronous processing which is considered as the major change in the specification. The i came across terms such as Executor, ExecutorService, Thread pool and wanted to read about it. I found a great article about the above area and decided to share it in my blog.
Implementing Thread Pools using Java Executors