CentOS

Check CentOS Version

cat /etc/*release*

or

$ cat /etc/redhat-release

install httpd

$ yum install httpd

Accept port 80

vi /etc/sysconfig/iptables

add line into iptables

-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT

restart iptables

service iptables restart