The definition shouldn't assume the reader has any technical knowledge (think tribal medicine man, or most people's grandmother)
The reason I ask is because I wanted to know if I was supposed to explain the computer to this person or just how it interacts with the internet.
Maybe the question could be "explain the internet to someone from 30 years ago. (Computers present, but no complete internet to speak of)"
Another quick question, is knowing what a computer is necessary for someone to understand the internet?
The question is also open to further interpretation: Is it, what the internet is, what it can do, how it works, what it means to society, or something else? There are many ways to "explain the internet" to someone with no knowledge of computers, but to explain how it is, or how it works, they must understand what a computer is.