When we sort through our feeds, “latest” has an obvious chronological sorting mechanism; even “popular” has a fairly clear and agreed-upon definition. “Trending,” however, does not. It’s similar, but not the same as “popular”; generally speaking, it means “popular, in some relative, technically defined way.” That is, the “trending” sections of major platforms are, as of now, algorithmically determined, their contents selected by formulas developed internally at those companies and kept private.