As mentioned later in the description, this page covers the 1984 Definitive Edition released as part of the Tezuka Complete Works.

The manga that made Tezuka famous. It is an action-adventure drama inspired by Robert Louis Stevenson's book.
One day a boy named Pete finds a map of "Treasure Island" that his deceased father left behind. He starts on a voyage to find it together with "Captain," who was a friend of his father. But his ship is attacked by pirates, led by Bowarl, and the two are caught. When a storm hits the pirate ship, the two are thrown into the sea and washed up on the shore of a solitary island in the southern ocean. To their surprise, this island is the one they have been looking for....
The Western-style art and fast-paced storyline attracted much attention, and it became a best seller with 400,000 copies sold, laying the groundwork for the manga craze and its modern style.
The original version of "New Treasure Island" was based on Tezuka Osamu's manuscript, but substantial modifications were made by Sasaki Shichima, who cut nearly 60 pages and also changed some of the lines. When publishing "The Complete Works of Tezuka Osamu," Tezuka Osamu remade it based on his memory to make it closer to his original.