BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
You’ve probably seen the movie a hundred times, so why not give the novelization a try? You just might enjoy the story in a whole new light, especially if you keep in mind that the novel came out shortly before the film’s release so this is how some fans experienced Empire Strikes Back for the first time. Imagine finding out about THAT spoiler through the book!
The adventures of Luke Skywalker did not end with the destruction of the Death Star.
Though the Rebel Alliance won a significant battle, the war against the Empire has only just begun.
Several months have passed, and the Rebels have established a hidden outpost on the frozen wasteland of Hoth. But even on that icy backwater planet, they cannot escape the evil Darth Vader’s notice for long.
Soon Luke, Han, Princess Leia, and their faithful companions will be forced to flee, scattering in all directions—with the Dark Lord’s minions in fevered pursuit.