An average galaxy measures up to sixty-thousand light years in diameter. The distance between one inhabited planet and the next is well over five light years far enough that conventional teleportation spells do not work. Most civilizations use a combination of two methods to get around the galaxy: hopping through the Strand for galactic distances and skimming the Current to cover intersystem distances.
The Strand is a heavily distored demiplane beneath the Material Plane. Short distances inside it translate to thousands of miles in the material plane, a property crucial to interstellar travel. Views of the Cosmos from within stretch into thin strands, originating the name.
To access the Strand, travelers use Waypoints: a series of specially-constructed arcane stations with planar capabilites. While useful, Waypoints are limited by location as they function best where the beile between the Material and the Strand is thin. As many as twenty neigboring star systems can be served by one Waypoint.
The Current is a network of magically flowing leylines that fuels the magic of the Cosmos. Its existance is formless and permeates throughout the Material Plane. Countless civilizations have built an engine that can briefly assimilate starships into the magic to propel them at high speeds in a proccess called skimming. Traveling the Current is slower compared to traveling the Strand, but is not restricted by location.
The Crossing the Galaxy section in Voidfaring Gear provides more information and rule for interstellar travel. Rare alternative methods exist, such as the mysterious Cosmic Gate or the experimental Recursion Circle.