Q:

What is the meaning of Role in Windows azure?

I am just not getting a feel about the meaning of Role in Windows Azure. 
There are two roles - Web Role (that has IIS Enabled) and Worker Role (Without IIS). 
What does Role mean?

A:

Per Mark Russinovich, Roles are like DLLs in the service process.
You can watch Mark Russinovich -Introduction to Windows Azure: the cloud operating system. The video is quite old; I watched it a few years back. 
Skip to 21:30 of Video.

