what is a protocol?

dont post stuff like question and answers dude!

first before going into the details of the protocol consider one thing...suppose u r talking to a teacher ...while talking to the teacher u will take care u dont talk any rubbish..that is u follow some etiquettes or rules....now these rules r nothing but protocols in the terms of networking...
hence protocols are nothing but guidelines which r to be followed in order to have a proper conversation..networking also consists of communication between two machines...therefore they follow protocols for every type of communication...that is for mailing they follow SMTP(simple mail transfer protocol)...for file transfer they follow FTP(file transfer protocol)...for browsing they follow HTTP(hyper text transfer protocol).