In the world of sheets, thread count refers to how many vertical and horizontal threads are per square inch. Generally speaking, higher numbers mean softer material that will wear well over time or even soften with use- though this isn’t always true as you can see from astronomical counts such as 1000 plus, which aren’t necessarily better than lower numbered sets but just have been inflated through tricks like using multiple yarns twisted together without adding any value for increased hand feel in fabric production.