Naruto is a story about a boy, a resident of the Hidden Leaf Village, who witnessed pain since he was born and strives hard to achieve recognition in his own village by vowing to himself to become the village leader. He shares a friendly relation with another kid Sasuke who is a genius unlike him who wishes to avenge the death of his clan by killing his elder brother.
(Naruto and Sasuke)
The first arc get over when Sasuke abandoned the Hidden Leaf village in order to grow stronger and Naruto vows to bring him back. At this time he finds out that an evil group Akatsuki is after him due to some evil spirit sealed inside him. This is where 'Naruto' ends as he leaves to train in order to become strong.(Naruto leaving with Jiraiya to train)
The event of Naruto Shippuden unfolds when this group makes its first appearance by kidnapping the leader of one of the 5 main villages in order to steal one of the 9 spirits that exist in the world.(Leader of Hidden Sand Village captured by Akatsuki)
As the story progress, Sasuke finally kills his brother only to find out that he was actually a spy who still was loyal to the leaf village. Feeling betrayed, Sasuke decides to destroy the village itself.(Itachi's death and Sasuke's regret)
In the meantime disaster struck Naruto as his master Jiraiya is killed by the leader of the Akatsuki.(The death of Jiraiya)
Soon the leader of the Akatsuki attacks leaf village in order to capture Naruto but is defeated.
It is soon reveled that the mastermind pulling the strings behind Akatsuki is a legendary ninja, Madara Uchiha who challenges the leader of all the 5 great nations into a war which results in the Fourth Great Ninja War.(The Shinobi Alliance Army and their 5 Captains)
Soon Sasuke accepts the feeling of his brother and decides to support Naruto in the war. The story is moving towards its final phase where the combined forces of Naruto and Sasuke is battling against their final enemy Kaguya who defeated Madara.