Is The Aeneid a real story or the real history of Rome?

The Aeneid is mostly myth. During the Age of Augustus, Virgil was asked to create the story of Rome's founding. It is important to note that there is another story about the founding of Rome involving the brothers Romulus and Remus. Both were said to have been suckled by a wolf. Later, Romulus kills his brother. The story of Romulus and Remus is also mentioned in the Aeneid. However, the epic poem does not focus on their adventures, but merely relates how they were necessary for the fate of the future republic and empire.
Instead, the poem focuses on the adventures of Aeneas, a Trojan soldier returning home after the end of the war. The Trojan War, too, figures somewhere between myth and actual historical record. During the Bronze Age, there was conflict between Troy (which is said to have been in what is now Turkey) and the Mycenaean kingdom. 
While some aspects of the poem are probably true, others are totally mythological. For example, in Book IV of the Aeneid, one of the best-known chapters, Aeneas falls in love with the Carthaginian queen Dido, but abandons her to fulfill his fated duty of founding Rome. In her grief, she commits suicide. It is very possible that Aeneas traveled to Carthage (what would now be Libya) and fell in love with a woman, then abandoned her.
On the other hand, Aeneas is said to have been the son of the prince Anchises and the goddess Venus. This aspect of his lineage is impossible. However, connecting Aeneas to a goddess explains why he is extraordinary and why he was fated to carry out such a monumental task.