1. First Install CUPS

yum install cups

2. Service Start and Stops 

systemctl enable cups
systemctl start cups 

3. Edit the Configuration file

sudo nano /etc/cups/cupsd.conf

Listen localhost:631

to

Listen *:631

grep -v '#' /etc/cups/cupsd.conf 

Managing temporary files with systemd-tmpfiles on Red Hat

Why the files in /tmp directory gets deleted periodically

For CentOS/RHEL7

cd /usr/lib/tmpfiles.d/tmp.conf

# cat /usr/lib/tmpfiles.d/tmp.conf
# Clear tmp directories separately, to make them easier to override
v /tmp 1777 root root 10d
v /var/tmp 1777 root root 30d

# Exclude namespace mountpoints created with PrivateTmp=yes
x /tmp/systemd-private-%b-*
X /tmp/systemd-private-%b-*/tmp
x /var/tmp/systemd-private-%b-*
X /var/tmp/systemd-private-%b-*/tmp

For CentOS/RHEL6

cd /etc/cron.daily/tmpwatch

# cat /etc/cron.daily/tmpwatch
#! /bin/sh
flags=-umc
/usr/sbin/tmpwatch "$flags" -x /tmp/.X11-unix -x /tmp/.XIM-unix \
	-x /tmp/.font-unix -x /tmp/.ICE-unix -x /tmp/.Test-unix \
	-X '/tmp/hsperfdata_*' -X '/tmp/.hdb*lock' -X '/tmp/.sapstartsrv*.log' \
	-X '/tmp/pymp-*' 10d /tmp

# man tmpwatch 

 Using Ubuntu Software Center

 Depends on Country wise but typical Indian govt also used ubuntu OS

Here is the offically website of ubuntu you can find more about it

https://ubuntu.com/gov

 No,

Better to go with DVD which start from 4.7GB

1. CD 700MB to 1.4GB

2. DVDs 4.7GB to 9.4GB, and 

3. BluRay Discs 25GB to 50GB