Can any one help me by explaining about few of my queries.?
in below examples. I have taken these lines from my file /etc/sysconfig/iptables (I have gone lot of tutorials about iptables but I could not get answer of these following.

-A INPUT -j RH-Firewall-1-INPUT (what this line intending to saying?)
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
(what is mean by -m ?)

-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
(what is mean by --icmp-type?)

-A RH-Firewall-1-INPUT -p esp -j ACCEPT
-A RH-Firewall-1-INPUT -p ah -j ACCEPT
(what is man by -p esp, and -p ah ? and what is the propose of these two lines?)

-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT
(Why this specific ip -d 224.0.0.251 is in my iptable file? what it is indicating it?)

-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
(what is the explanation of this line?)

-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 21 -j ACCEPT

(in above line what is mean by
-1
-m state
-- state NEW
again -m
)
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
(what is the explanation of this above line?)

Hi, tolkali. Welcome to LinuxQuestions.
This is something you might read that will answer your questions. On that site you will also find downloadable versions of the tutorial.

Thanks Berhanie!! The document link you have provided is very much interesting and I love to go through it. If I can not understand again I will speak here.
Thanks for your support.

Very good, tolkali. I'll see you around the forums, then. Good luck, and welcome.