The word "genesis" comes from the Greek word "geneseos," which can mean "birth", "history of origin", or "geneology". This is an appropriate title for the first book of the Bible, as the book of Genesis deals with beginnings.
The book of Genesis begins by telling the story of creation - the involvement of God in causing the formation of the planets and stars, of environment and vegetation, of animals in the sea, in the air, and on land, and finally of humanity.
Genesis relates the earliest attempts by God to establish right relationship with the humans on Earth, and of the ways in which humans rebelled or repulsed those efforts. Prehistoric events included in Genesis feature the Garden of Eden, the ark allowing Noah and his family and representative animals to survive the great flood, the tower of Babel resulting in a diversity of spoken languages.
The second half of Genesis focuses on the family of Abram, later renamed Abraham, who becomes the father of the tribe of people selected to become God's "chosen people." Abram is called to move his family away from his homeland to an area where God can begin to shape a new people, following a new, monotheistic faith and a lifestyle based on obedience and faith in that one God.
The LORD had said to Abram, "Leave your country, your people and your father's household and go to the land I will show you. I will make you into a great nation and I will bless you; I will make your name great, and you will be a blessing. I will bless those who bless you, and whoever curses you I will curse; and all peoples on earth will be blessed through you. (Gen. 12:1-3)
Abram follows God's leading. He is renamed Abraham, which means "father of many." In his old age, he and his wife Sarah have a son, Isaac. Isaac's son Jacob becomes the patriarch of the Israelite nation, as the descendents of his twelve sons become known by their names.
Through the experiences of the Israelites, God demonstrates great love and desire to be faithful to humanity but demands that humanity live in accordance with God's expectations in return. The relationship between God and God's chosen people, sometimes in obedience with peace and prosperity, often in disobedience with punishment and suffering until the people repent, is an overarching theme for the entire Bible.