It is the first area or stage that Samus Aran traverses through, and can arguably be considered the "training stage" of the game. The ship is filled with Galactic Fedration marines and troopers, including multiple different bounty hunters including Samus, Rundas, Ghor, and Gandrayda.
Soon into the adventure, an army of Space Pirates will come and attack the ship, requiring Samus Aran to escape and fight the first boss of the game: the Berserker Lord, who appears moments before she reaches her ship.
The GFS Olympus is 20 years old, and was the first ship of that size to obtain an Aurora Unit. The Aurora Unit stationed here, number 217, will aid Samus Aran throughout her whole adventure, and will oftentimes give her hints as to where to go next.