Anakin Skywalker and Ahsoka Tano escaped from Teth aboard the battered spice freighter Twilight, surviving a crash landing on Tatooine. Anakin had the ship salvaged and repaired for a number of reasons. He'd become fond of her, she'd proved surprisingly maneuverable, she offered Anakin plenty of opportunities for tinkering with machinery, and a nondescript freighter could prove useful on secret missions.
Anakin Skywalker "borrowed" the Twilight from a landing pad on Teth when he needed a vehicle to escape a Separatist occupation. He took a shine to the grimy freighter, and has tinkered with its systems, modifying the vessel to become his unofficial starship for non-Jedi duties.
Together, Anakin and Ahsoka occasionally bend the rules of the Jedi Order and Republic military and go off on "unapproved" missions. To do so, their ship of choice is the Twilight, which bears no Republic colors or identification.
The Twilight was originally part of Ziro the Hutt's criminal organization. The colorful gangster kept the freighter fueled and ready to fly atop a landing platform on Teth.
Astromech droid R2-D2 is a well equipped shipboard mechanic -- and his skills were pressed to the limits aboard the Twilight. Anakin's constant tinkering with the freighter meant R2-D2 was kept busy patching modifications and rebooting overpowered systems.
When the Twilight was outrunning starfighters dispatched by the cruiser Malevolence, Padmé showed off her gunnery skills by operating the ship's laser cannons from a rotating periscope station.