The problems and solutions uses the problem description given by the customer to search for aappropriatesolutions that can be returned to the customer.
It often comes up as a search result list, which can be further truncated by filtering according to attributes.
A knowledge article is a piece of info that can be used to resolve an issue, where details can be added as well. A knowledge article is connected to a business transaction.
Your case seems to be a problem and solution scenario.