Please give me Information about System Users Described in RHEL
 

I want to know the Significance of following System Users

root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
#lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
#mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
#news:x:9:13:news:/etc/news:
#uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
#games:x:12:100:games:/usr/games:/sbin/nologin
#gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
#ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
#nobody:x:99:99:Nobody:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
nscd:x:28:28:NSCD Daemon:/:/sbin/nologin
rpm:x:37:37::/var/lib/rpm:/sbin/nologin
haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
netdump:x:34:34:Network Crash Dump user:/var/crash:/bin/bash
ident:x:98:98::/home/ident:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
rpc:x:32:32:Portmapper RPC user:/:/sbin/nologin
rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
#nfsnobody:x:4294967294:4294967294:Anonymous NFS User:/var/lib/nfs:/sbin/nologin
#mailnull:x:47:47::/var/spool/mqueue:/sbin/nologin
#smmsp:x:51:51::/var/spool/mqueue:/sbin/nologin
pcap:x:77:77::/var/arpwatch:/sbin/nologin
#apache:x:48:48:Apache:/var/www:/sbin/nologin
#squid:x:23:23::/var/spool/squid:/sbin/nologin
#webalizer:x:67:67:Webalizer:/var/www/usage:/sbin/nologin
xfs:x:43:43:X Font Server:/etc/X11/fs:/sbin/nologin
#ntp:x:38:38::/etc/ntp:/sbin/nologin
gdm:x:42:42::/var/gdm:/sbin/nologin
#htt:x:100:101:IIIMF Htt:/usr/lib64/im:/sbin/nologin
#pvm:x:24:24::/usr/share/pvm3:/bin/bash
#canna:x:39:39:Canna Service User:/var/lib/canna:/sbin/nologin
#wnn:x:49:49:Wnn Input Server:/var/lib/wnn:/sbin/nologin
#quagga:x:92:92:Quagga routing suite:/var/run/quagga:/sbin/nologin
#cyrus:x:76:12:Cyrus IMAP Server:/var/lib/imap:/bin/bash
#dovecot:x:97:97:dovecot:/usr/libexec/dovecot:/sbin/nologin
#postfix:x:89:89::/var/spool/postfix:/sbin/nologin
#mailman:x:41:41:GNU Mailing List Manager:/usr/lib/mailman:/sbin/nologin
#mysql:x:27:27:MySQL Server:/var/lib/mysql:/bin/bash
#postgres:x:26:26:PostgreSQL Server:/var/lib/pgsql:/bin/bash
amanda:x:33:6:Amanda user:/var/lib/amanda:/bin/bash
#fax:x:78:78:mgetty fax spool user:/var/spool/fax:/sbin/nologin
#named:x:25:25:Named:/var/named:/sbin/nologin
exim:x:93:93::/var/spool/exim:/sbin/nologin
ldap:x:55:55:LDAP User:/var/lib/ldap:/bin/false
#radiusd:x:95:95:radiusd user:/:/bin/false
#radvd:x:75:75:radvd user:/:/sbin/nologin

Thanx and gratitude in advance for your replies.

Hi and Welcome to LQ.

As you may know the 2 main users are root and user(insert username here)

The rest are, as you have listed them, System users.

They are for the system to operate and take little notice of anything else.

Most of the descriptions are there in your list. The others you can google to find out what they do.

I hope this helps, you may want to look up the "Linux Documentation Project"

http://tldp.org/guides.html

regards Glenn