what is the config files for, and how to change?

[ender049]

excuse me. my english is not very well. and I have had a look at the docs. just not very clearly.
there is so many config files . which is for what? and after edit it ,how to take effect?

for example:
in /etc/ispcp/
there is so many config files. which one is for what? there are parts and working folder. I know that the parts folder is the template files, when add new site will be used. and the working folder for what?

and the /etc/ispcp/ispcp.conf file,after change it ,what should next step to do for taking effect?

sorry for this newbie question. but I think it is better having a page to tell every body that after installation, every file of ispcp is for what and how it work.