In 2012, Neil Young started making waves (ha! - OK, that was an accidental pun) about how the public is consuming audio in a very low-resolution way. For instance, the files you listen to on your iPod, iPhone or other mobile device are data-compressed. That means that files like mp3s and aac audio files have had information removed and rearranged from the original master audio in order to reduce the file size so they can be streamed more easily over the internet. This is why you can put thousands of songs on an iPod too. Young wants the public to be able to listen to the full sound of "high resolution" audio. So he invented a thing called "Pono." It's a digital player that would let you hear "the full audio," instead of the mp3s and aacs we're listening to now.
The process of creating good-sounding version of much smaller file-sizes for audio began in the early 90s with the mp2 and then mp3. To give you an example of the difference in file size between what is on a CD and the mp3 version - if you take a song from a CD and convert it (people call this "ripping" for some reason) to mp3, you end up with a file that is about a tenth the size of the original file on the CD. For example, a song on a CD might be a 40MB wav file. But when ripped to mp3, it ends up only 4MB.
Additionally, even the files on the CD are technically lower quality than the master recording. CD standards require a 16-bit file (see our article on bit-depth in audio recording) and a 44.1 KHz sampling rate (see our article on sampling frequency). But master recordings used to make those CDs are almost always 24-bit and either 48KHz or 96 KHz. So even CDs are "lower rez" than the master recording.
On top of all that, mastering audio can be even higher resolution than 24/96! Some masters are using 192KHz. So it might be natural to think that since 24-bit/96KHz (some call this the minimum "bona-fide high-resolution audio") is being reduced to 16-bit/44.1KHz on a CD, and then further reduced to create mp3s, that end product on your device should sound like ass, right? Well I'm betting that a good "99-point-a-whole-bunch-more-9s" percent of people could not tell the difference between any of these resolutions. It isn't like your TV screen, where the difference between standard and HD is painfully obvious to most people. In audio, it just isn't so obvious.
However, a small percentage of true audiophiles can certainly hear a difference, and they think it's a shame that the audio consuming public is mostly listening to what they consider to be inferior quality audio. One such person is Neil Young. There was a large publicity push about Pono in 2012. But then it seemed to quietly fade as an idea. So what is the latest status? Take a look at this article for the latest on Pono.