Difference between Standard & Xinetd based services

When you run “chkconfig -list”, you would see 2 set of service list.  One portion is termed as “Standard” service and other one as “xinetd” (Extended Inetd) based services. 

Main difference between these 2 set of services:

Standard services	Xinetd based services
Will be started/stopped based on the run level	Doesn’t depend on run levels
Once turned on, it will continue to run till it stopped	The dameon ‘xinetd’ controls starting and stopping the service as and when it requires. The xinetd dameon listens for requests coming for particular port and starts the relevant service pertaining to it. For example, when telnet is turned on, it listens for request on port 23 and start the telnet service when there is a telnet connection request.
Service should be continuously running regardless of its usage. For example, in the below output, cups service is continuously though it isn't required for many servers. This can be turned off.	Xinetd dameon performs the job of continuously monitoring the service request under its control and activate it only when it is required.

[root@host01-tx ~]# chkconfig --list

NetworkManager  0:off   1:off   2:off   3:off   4:off   5:off   6:off

acpid           0:off   1:off   2:on    3:on    4:on    5:on    6:off

anacron         0:off   1:off   2:on    3:on    4:on    5:on    6:off

apmd            0:off   1:off   2:on    3:on    4:on    5:on    6:off

atd             0:off   1:off   2:off   3:on    4:on    5:on    6:off

auditd          0:off   1:off   2:on    3:on    4:on    5:on    6:off

autofs          0:off   1:off   2:off   3:on    4:on    5:on    6:off

bluetooth       0:off   1:off   2:on    3:on    4:on    5:on    6:off

capi            0:off   1:off   2:off   3:off   4:off   5:off   6:off

certmaster      0:off   1:off   2:off   3:off   4:off   5:off   6:off

conman          0:off   1:off   2:off   3:off   4:off   5:off   6:off

cpuspeed        0:off   1:on    2:on    3:on    4:on    5:on    6:off

crond           0:off   1:off   2:on    3:on    4:on    5:on    6:off

cups            0:off   1:off   2:on    3:on    4:on    5:on    6:off

httpd           0:off   1:off   2:off   3:off   4:off   5:off   6:off

iptables        0:off   1:off   2:off   3:off   4:off   5:off   6:off

.
[ Output truncated ]

.

xinetd based services:

        bpcd:           on

        bpjava-msvc:    on

        chargen-dgram:  off

        chargen-stream: off

        .

        [Output truncated]
        .     

[root@host01-tx ~]# ls -l /etc/xinetd.d            #  location of xinetd config files

.
[output not shown]
.

[root@host01-tx ~]#

[root@host01-tx ~]# ps -ef | grep cups | grep -v grep    # Cups service is continuously running

root      4483     1  0 Jul25 ?        00:00:24 cupsd

 [root@host01-tx ~]# ps -ef | grep bpcd | grep -v grep   # Bpcd service is not running though it is turned on

[root@host01-tx ~]# ps -ef | grep bpjava-msvc | grep -v grep  # bpjava-msvc isn't running as well

[root@host01-tx ~]#