You can convert FLAC files to any other format (like AAC or MP3) in the future without losing any additional quality.
The mention of "CU" likely refers to CUE files , which provide the metadata and track timing for the disc images, ensuring the gaps between songs are preserved exactly as they were on the original albums. Discography Timeline Highlights (1974–2011)
This collection spans several distinct eras of the band's history:
This specific file string describes a comprehensive, high-fidelity digital library of Judas Priest’s most influential decades. It is intended for listeners who prioritize audio quality and want a complete historical record of the band's evolution from bluesy hard rock to the "Godfathers of Heavy Metal."
Halford's return to the band, resulting in Angel of Retribution and the concept album Nostradamus . Technical Value of the FLAC Format