[ADMIN] POSTMASTER

[Gagan]

Respected sir/madam,

I have been able to access the databases of my postgresql immediately after
logging on to my postgres user. But i am confused about POSTMASTER
application. Following r my querries regarding POSTMASTER :

1. What is the main utility of this application?
2. Is it executed automatically at startup of my Linux OS?

I will be obliged to get by mind out of these confusions.

regards
Gagan