How Many Files Need for input in Nagios ??like (windows.cfg)

[mohsin2011]

hi i am new to this apps but i trying to create my own apps i am willing to know that how many apps are there from which we can input our data or our output result depends upon those file like "Template.cfg" and "windows.cfg" where we can add host and there services
Actually i creating my own apps like nagios so i will create forms form which we can create input files like "Template.cfg" and "windows.cfg" so that we cna use this apps is there some other file like that which will take input and our output depends upon those files and if so then please mention me there names and there purpose

Hopes for your reply

Thanks in Advance !