modules.conf Configuration of modules that enable special features (drivers).
motd Message Of The Day: Shown to everyone who connects to the system (in text mode), may be used by the system admin to announce system services/maintenance etc.
mtab Currently mounted file systems. It is advised to never edit this file.
nsswitch.conf Order in which to contact the name resolvers when a process demands resolving of a host name.
pam.d Configuration of authentication modules.
passwd Lists local users. Use the shadow utilities useradd , usermod and userdel to edit this file. Edit manually only when you really know what you are doing.
printcap Outdated but still frequently used printer configuration file. Don't edit this manually unless you really know what you are doing.
profile System wide configuration of the shell environment: variables, default properties of new files, limitation of resources etc.
rc* Directories defining active services for each run level.
resolv.conf Order in which to contact DNS servers (Domain Name Servers only).
sendmail.cf Main config file for the Sendmail server.
services Connections accepted by this machine (open ports).
sndconfig or sound Configuration of the sound card and sound events.
ssh Directory containing the config files for secure shell client and server.
sysconfig Directory containing the system configuration files: mouse, keyboard, network, desktop, system clock, power management etc. (specific to RedHat)
X11 Settings for the graphical server, X. RedHat uses XFree, which is reflected in the name of the main configuration file, XFree86Config. Also contains the general directions for the window managers available on the system, for example gdm , fvwm , twm , etc.
xinetd.* or inetd.conf Configuration files for Internet services that are run from the system's (extended) Internet services daemon (servers that don't run an independent daemon).
Throughout this guide we will learn more about these files and study some of them in detail.
