2 Samuel is in the Old Testament of the Bible. It is a history book. We can learn many lessons for our own lives from the events in this book.
The book of 2 Samuel is about King David. The book discusses the events while David was king. David's soldiers fought many wars. They obtained the city of Jerusalem in a successful battle (2 Samuel 5). Jerusalem became their capital city.
David loved God. David was a good king, but he made some terrible errors. He had sex with a married woman called Bathsheba (2 Samuel 11). And David ordered the death of Bathsheba's husband. Later, David confessed his evil deed to God (Psalm 51).
Afterwards, David's own son, Absalom, fought against David (2 Samuel 18).
But God saved David from all his enemies (2 Samuel 22).