3.1.7 Explain why protocols are necessary

Protocols are the set of rules computers follow when communicating across a network. 
Without them, no information can be transmitted as computers don't know how to interpret the signals coming through the network. 

Essential functions of protocols 
• Ensure data integrity 
• Manage flow control 
• Prevent deadlock 
• Manage congestion 
• Perform error checking

Some protocols also support data compression designed for high-performance network communication. Hundreds of different computer network protocols have been developed, and each one of these has been designed for a different purpose or environment. You need protocols in computer networks because computer networks consist of devices and software made by many different companies. The only way to ensure compatibility among them all is to have common protocols that describe the mechanics and formats of all the data exchanged over the network