configuration filename is based on the name of the application for which
it contains settings. Such a naming convention allows you to more readily
determine which configuration file contains settings for a given
application.

System-Wide Versus User-Specific
Configuration

It's important to remember that there are two different kinds of
configurations on a Debian system. System-wide configuration affects all
users. System-wide settings are made in the /etc directory, so you
generally must be root in order to change system-wide settings. You might
configure the way the system connects to the Internet, for example, or
have web browsers on the system always start on the company home page.
Since you want these settings to apply to all users, you make the changes
in /etc. Sample configuration files in /etc include /etc/X11/XF86Config,
/etc/lynx.cfg, and /etc/ppp/options. In fact, nearly all the files in /etc
are configuration files.

User configuration affects only a single user. Dotfiles are used for user
configuration. For example, the file ~/.newsrc stores a list of which
USENET (discussion group) articles you have read and which groups you
subscribe to. This allows news readers such as trn or GNUS to display
unread articles in the groups you're interested in. This information will
be different for every user on the system, so each user has his own
.newsrc file in his home directory.

Aliases

If you use the same command often, you might get tired of typing it. bash