what is protocol?

protocol is a set of routines that help for data communication b/w systems. it just acts as a bridge for passing the data. there are many types of protocols. internet uses 1) TCP IP Protocol. ie. transmission control protocol.
SMTP - simple mail transfer protocol.
ip - internet protocol which is 127.0.0.1 by default on ur machine when even not connected to internet.

Thank u. good day.

Protocol is a set of rules which must be followed while transfering data over the internet.there are specific protocols for separate applications.like http,https,ftp,ppp

Protocols are set of rules which do particular task. Different protocols are used for different tasks like smtp, tcp/ip, http, ftp....etc. smtp used in transfer the mails and tcp/ip chops the data and send it to its destination.

In computing, a protocol is a convention or standard that controls or enables the connection, communication, and data transfer between two computing endpoints. In its simplest form, a protocol can be defined as the rules governing the syntax, semantics, and synchronization of communication. Protocols may be implemented by hardware, software, or a combination of the two. At the lowest level, a protocol defines the behavior of a hardware connection.