Many modern computer activities are too complex for the system
simply to look at a file or some other static resource. Sometimes
these activities need to
interact with another running process.
For instance, take FTP, which you may have used to download
some Linux-related documents or software.
When you FTP to
another system, another program has to be running on that system to
accept your connection and interpret your commands. So there's a
program running on that system called ftpd. The d in
the name stands for daemon, which is a quaint Unix term for a
server that runs in the background all the time. Most daemons handle
network activities.
You've probably heard of the buzzword client/server enough to
make you sick, but here it is in action--it has been in action for
years on Unix.
In the next section, we'll show you how to see which daemons are
running on your system. There's a daemon for every service offered by
the system to other systems on a network: fingerd to handle
remote finger requests, rwhod to handle
rwho requests, and so on. A few daemons also handle
nonnetworking services, such as kerneld, which
handles the automatic loading of modules into the kernel.
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4.16. Important Directories |  | 4.18. Processes |