Herodotus was born in Halicarnassus and lived from 484 until 429 B.C. These dates are approximate.
The History of Herodotus is divided into nine 'books' (we would call it chapters) each with a name of one of the nine Muzes: book 1 is Cleio, book 2 is Euterpe, book 3 is Thaleia, book 4 is Melpomene, book 5 is Terpsichore, book 6 is Erato, book 7 is Polymnia, book 8 Ourania and book 9 Calliope. Their names were given at random without a link to the content of each book. Scholars believe that it wasn't Herodotus who used these names but that it was done probably by an unknown copyist from the Hellenistic period (+- 300-200 B.C.).
Many critics say that there is no leading thread running through the nine books and that their digressions are used haphazardly with little explanation of historical events. Those critics are not entirely wrong. Herodotus is fond of legends, myths and anecdotes ( in book 2 for instance we read an Egyptian horror story ) and let's face it; the Greeks themselves were fond of these things. Herodotus must have been a very popular writer in his time. Modern historians though are not likely to use such things with minor importance in their scientific works.
There is a leading thread however but you have to simplify things a little. You could summarize Herodotus' work in three steps. 1. How Persia becomes a military power. 2. The conquest of Egypt by Persia. 3. Two attempts to conquer Greece and why they failed. The first attempt fails in the battle of Marathon (490 B.C.). The second attempt is more complex but takes a turn in favor of the Greeks during the sea-battle of Salamis where the Persian fleet is almost destroyed. Legend ( or historical fact ? ) has it that Aeschylus - one of the three Tragedy Poets - participated in that battle. ( 480 B.C. ).
Herodotus proofs that literature from Antiquity can be entertaining.