All, speech requires prior knowledge to be understood. Usually this is largely shared within a culture. So if I say “the cat” I do not usually have to tell you first what a cat is. (Even if in the context of a novel about old-time sailors it might be a whip.) Some courses of study have organised “prerequisites” courses you must take before them. Many books have a preface or prologue that cointains material the author thinks you need to know before tackling the body of the work.
Genesis 1-11 is the prologue to the Bible, The “characters” and themes it introduces will help us understand the whole of the rest.