Byte
A byte was a unit of computer storage. 

In 2364, the Bynars performed a computer core dump from Bynaus in the . This act filled every byte of free space in the starship's computer core. ()

Comparative list of storage measurement 
Gigabyte = 1 billion bytes
 Gigabytes. Nanites being studied by Wesley Crusher in the 24th century had "gigabytes of mechanical computer memory". ()
 300 gigabytes. Commodore Oh accused Dr. Agnes Jurati of transferring 300 gigabytes of  concerning Bruce Maddox to a PADD, and presumably giving it to Jean-Luc Picard. ()
 3,000 gigabytes. Henry Starling noted that when Captain Janeway and Commander Chakotay attempted to download his database, they had downloaded 3,000 gigabytes of data when Starling forced them to terminate their download. ()

XB
 19.3 XB. D'Jamat deleted 19.3 XB of data  had collected on the Delphic Expanse spheres. ()

See also

Quad

External link
 

de:Byte
Measurements
Computer technology