If we do not speak about the world as such, we can speak only about data and their interpretation, that was what Ernst Mach and Heinrich Hertz had considered. Yet if we speak about interpretations of data we can be much more precise: Our interpretations only make sense as far as they consist of statements about facts.
A statement about a fact can upon research turn out to be "the case" - we define what we prove and what we accept as a positive test result. The rest is logic, since now we can define that a statement only makes sense insofar as we can think of a situation in which we would say "yes, this is the case, positively proven".
The area of statements that make sense is wide. Some happen to be the case. Statements about facts are hence a subset of meaningful statements. (Two moons circulate around the Earth is a meaningful statement, yet upon observation not the case.)
Once we go that far we can see what kind of statements are not statements of this special class. "Thou shalt not kill" is a statement of quite a different class. What is the fact if this is true? The statement rather expresses a command than a verifiable situation. The world of facts has peculiar borders given with the world of verifiable statements. The subject is rather a grammatical entity in these statements, so the consideration that leads into further thoughts about how we use language.
Ludwig Wittgenstein's considerations are in the 1920s embedded in a move of debates promoted by groups such as the Vienna Circle with Rudolf Carnap, Kurt Gödel, Hans Hahn, Otto Neurath. The second wave of considerations that dealt basically with language and the questions how we link our statements to the world inspired linguists and philosophers in the greater movement of the linguistic turn that led toward structuralism and post-structuralism as large interdisciplinary movements of thought.