The authorship of the first five books of the Bible is attributed to Moses. He recorded the oral accounts passed on from prior generations to write Genesis, while he is the central figure (aside from God) for the events in the other four books. These five books, sometimes called the Pentateuch or Torah (the law), are:
Exodus is about the nation of Israel escaping their captivity in Egypt and fleeing; it is their exodus from Egypt.
Leviticus is a record of rules and regulations for the right living of God’s chosen people.
Numbers is an account of Israel’s wanderings in the desert and contains two censuses (that is, numberings) of the people.
Deuteronomy is the book of laws, not in a narrow sense, but in a narrative form as presented by Moses.