What is a network protocol?
Why Interviewers Ask This
Interviewers use this question to quickly assess whether a candidate has the foundational knowledge required for Networking development. It reveals whether you understand the building blocks that more complex concepts rely on.
Answer
A network protocol is a set of rules and conventions that govern how devices communicate over a network. Protocols define the format of messages, the sequence of exchanges, error handling, and how to establish and terminate connections. Without protocols, devices from different manufacturers could not communicate. Protocols exist at every OSI layer: Physical (Ethernet, Wi-Fi), Data Link (Ethernet 802.3, PPP), Network (IP, ICMP, OSPF, BGP), Transport (TCP, UDP), Application (HTTP, FTP, SMTP, DNS, SSH). Protocols are typically defined in RFCs (Request for Comments) published by IETF (Internet Engineering Task Force). Standardization allows interoperability — your MacBook can browse a website on a Windows server because both follow the same HTTP, TCP, and IP protocols.
Common Mistake
Don't just define the term — demonstrate that you understand when to use it and when not to. Showing awareness of trade-offs is what separates average from strong Networking candidates.