Gobal Information Distribution Daemon.

global information distribution. Process that runs on the NP of every LightStream 2020 ATM switch in a network. GID maintains a database and keeps nodes in the network apprised of changes in topology such as ports, cards, and nodes being added or removed, and trunks going up or down. This information is supplied by the ND process. Sometimes called global information distribution daemon, or GIDD.

In SERVER SIDE: nfsd statd lockd nfslogd mountd In CLIENT SIDE: statd lockd

A 'daemon' is a software process that runs in the background (continuously) and provides the service to client upon request. For example named is a daemon. When requested it will provide DNS service.
Other examples are:
xinetd (it is a super-daemon, it is responsible for invoking other internet servers when they are needed)
inetd (same as xinetd, but with limited configuration options)
sendmail/postfix (to send/route email)
Apache/httpd (web server)
'server process' run runs one time, when called by a daemon. Once done it will stop. For example telnetd (in.telnetd) or ftpd called from xinetd/inetd daemon . By calling server process from daemon you can save the load and memory. Use a server process for small services such as ftpd, telnetd.

Gracefully  restarts  the  Apache httpd daemon. If the daemon is not running, it is started. This differs from a
normal  restart in  that  currently  open  connections  are not aborted. A side effect is that old log files will  not
be  closed  immediately. This  means that if used in a log rotation script, a substantial delay may be necessary to ensure that  the  old  log  files  are closed before processing them. This command automatically checks        
    the configuration files as in configtest before initiating  the restart  to  make sure Apache doesn?t die.
This is equivalent to apachectl -k graceful.
( excerpt from manual page of apachectl )
Actually it sends a SIGUSR1 for a restart. The USR1 or graceful signal causes the parent process to advise the children to exit after their current request (or to exit immediately if they're not serving anything). The parent
re-reads its configuration files and re-opens its log files.As each child dies off the parent replaces it with a child
from the new generation of the configuration, which begins serving new requests immediately.

Daemon stands for Disk and Execution Monitor. A daemon is a long-running
background process that answers requests for services.
The processes like vhand, bdflush, sched are housed in kernel file or /unix system
which are known as daemons. These files run in the background without users request.These are created when the system boots up and remains active till it shut
down or hang. These are not linked to any user or any terminal .We can't kill a
daemon.