Worker process and application pool

Question

Hi everyone,

I went through a couple of articles over the net to understand worker process and application pools but somehow i am having troubles understanding them.
Can someone help me understand in simple words  what is  an application pool and how the app pools contain worker process.
does our .net application run in a worker process ?
When a client requests for a asp.net resource, the request goes to the worker process which in turn provides the response ?

Thanks