At the heart of every Jedi lightsaber is a kyber crystal found on several planets, most notably the icebound caves of Ilum. This crystal is attuned to the Force, and connected to a Jedi Knight on a deeply personal level. In this way, a lightsaber is an extension of a Jedi's Force awareness. Because Jedi let the Force guide their selection of the crystal, the vibration that the crystal creates in the lightsaber blade helps Jedi center themselves and find balance in the Force. In this way, a Jedi can center his or her attention beyond the distractions of combat. A lightsaber crystal is colorless until first attuned and connected to a Jedi -- at which times it glows either blue or green, or in some rare instances, another shade. From that point on, it retains that hue.
The wedge-shaped Imperial Star Destroyer is a capital ship bristling with weapons emplacements. Turbolasers and tractor beam projectors dot its surface. Its belly hangar bay can launch TIE fighters, boarding craft, land assault units, hyperspace probes, or be used to hold captured craft. In the days of the Empire, its bustling bridge would be staffed by the finest crewers in the Imperial starfleet. Its presence in a system mark matters of extreme Imperial import. Though, as is typical of the Empire, not even the Star Destroyer was enough to sate the Imperial hunger for displays of power. Larger vessels, such as the Super Star Destroyer, dwarf even these giants.
A small desert moon frosted by a permanent winter, Jedha is home to one of the first civilizations to explore the nature of the Force. At one time a world important to the Jedi Order, Jedha serves as a holy site for pilgrims from across the galaxy who seek spiritual guidance. Now, the Empire occupies Jedha, and a prolonged battle between Imperial forces and scattered Rebels carries on in the timeworn streets.