Protocol
A protocol is a set of rules which determines how the data will be transmitted over in the network. Protocol are stored in binary information. It is a mixture of bits, characters, and integers.
Suppose there are 2 machines and we need to transfer some data to another machine. In this case of data transfer, there are some rules, which are known to us as Protocol. So, we can say that in networking protocol is a set of instructions that define how data will be transferred and how devices will communicate with each other. It is a communication standard which helps to communicate two devices. There are 3 levels in a protocol. These are:
1. Hardware Device Level
2. Software Level
3. Application Level
And there are 2 types of protocol:
1. Standard Protocol:
Standard protocol helps to communicate multi winder means products of a different company.FTP,DNS,DHCP,SMTP,Telnet,TFTP are the standard protocol which are available for public users.
2. Proprietary Protocol:
A proprietary protocol cannot support multi winder. It can support only company own devices. This is not available publicly. If anyone wishes to use that proprietary protocol, then he/she have to take permission of that protocol company means by which the protocol was created. Let's talk about IMessage which has made by Apple. If there are two Apple devices then by the proprietary protocol the communication could be possible. But in the case of other company devices, it will not be possible.