Why do we use protocols in networks? Give 3 examples of application layer protocols.

Protocols are the common set of rules that every networking device has to follow in order to communicate with the other networking device in the network. 

Examples are HTTP, SMTP, DHCP, FTP etc

Network protocol describe the rules for communication between network devices.

Application layers : DNS , SMTP, FTP

its  rules and conventions to communicate between network devices. SMTP, SNMP,FTP

Protocols are certain sort of rules that help us make our communication possible with network.Here the protocols are used in Application layer helps users to communicate with different Applications.

1.Telnet ---Able to remote logging with the system.Communcations are in clear text format

2. SSH----- A more sure protocol than Telnet.Here communication are in an encrypted format

3.FTP    ----File Transfer Protocol helps to transfer files between systems

First of all you should to know  

what are  protocols? 

protocol is set of roles that govern data communication . 

so 

 We use protocols to communicate with anther computers  .   

1- FTP, File Transfer Protocol.

2- HTTP, Hypertext Transfer Protocol.

3- HTTPS, Hypertext Transfer Protocol Secure.

4- Telnet, a remote terminal access protocol.

5- DHCP, Dynamic Host Configuration Protocol.

communication with other computers in network.data is carried by protocols ,without it the network will not work .FTP,DHCP,POP, HTTP,SMTP.......ETC