What is the difference between a protocol standard and a protocol implementation?
A protocol standard is a system of rules. A protocol implementation is a software component that applies those rules in order to provide networking capability to a computer.
Why did the designers of ARPAnet want a decentralized network?
They envisioned a network that would be used for military purposes, and they didn't want to concentrate critical services in a central location that could become the focus of an attack.
Why was end-node verification an important feature of ARPAnet?
By design, the network was not supposed to be controlled from any central point. The sending and receiving computers, therefore, had to take charge of verifying their own communication.
Why do larger networks employ name resolution?
IP addresses are difficult to remember and easy to get wrong. DNS-style domain names are easier to remember because they let you associate a word or name with the IP address.