A concept handle is a memorable noun or phrase representing a complex, often abstract topic. For example, there’s knowledge gained through experience, first-hand knowledge, and there’s knowledge gained through reading books or talking with people, second-hand knowledge. This concept handle gives us the vocabulary to describe and communicate these ideas. Other concept handles I wrote in the past are kamiwaza, idea flux, and sonder.
I love learning new concept handles, and when I do I nearly always write about them, because they make the abstract tangible.