What is a Windows Service and how does its lifecycle differ from a "standard" EXE?

Windows service is a application that runs in the background. It is equivalent to a NT service. The executable created is not a Windows application, and hence you can't just click and run it .
It needs to be installed as a service, VB.Net has a facility where we can add an installer to our program and then use a utility to install the service.
Where as this is not the case with standard exe