Final answer:
An IP address is a unique identifier for devices on a network, a domain name is a human-friendly website address, a web navigator is a browser to access the internet, and a software agent is a program that performs tasks on behalf of a user.
Step-by-step explanation:
The IP address (Internet Protocol address) refers to a unique identifier assigned to each device on a network, including the internet. It serves as a digital address, which allows devices to communicate with each other across networks. An IP address is not to be confused with a domain name, which is a more human-friendly way of accessing websites (e.g., 'www.example.com') rather than using numerical addresses. A web navigator, which can also be known as a web browser, is a software application used to access and navigate the internet. Lastly, a software agent is a computer program that acts for a user or other program in a relationship of agency, which means it can perform tasks or gather information on behalf of a user.