Literacy is actually a good analogy. People have different reading abilities, but they're all under the umbrella of literacy.

Some people are illiterate, some people can read simple documents but struggle with higher complexity texts and contracts, and some people can breeze through high complexity texts. In the same way, some people struggle with computers, some are able to understand Excel spreadsheets, some are able to understand business logic expressed in a domain specific language, and some are able to read complex programs.