I am often asked about the difference between lossy and lossless and what it actually means. I am also asked why our DAC natively only supports one and not the other.
Lossy means to lose something: in this case, musical information. Lossless, means the opposite: all the musical information is preserved.
Why would we want one over the other?
Both terms refer to compression, the practice of squeezing more out of less. In this case, more data in less space. There was a time when memory and bandwidth were more precious than they are today. And back then whatever designers could do to squeeze more data into a smaller space meant more songs could be placed on hard drives, and hard pressed networks could stream music to more people without clogging up.
More, more, more.
There's only so much you can do to squeeze more into a smaller space if you're unwilling to lose information. Lossless file types, like FLAC and ALAC, squeeze about twice as much data into the same size container as their uncompressed versions. To get more data into a smaller space you need to start giving up some of your data. Lossy.
Lossy files can range from not losing much to losing a hell of a lot, and everywhere in between. The most famous of the lossy files is MP3. What's interesting about MP3 is its variability. MP3 can range from the very compressed to the not so compressed, depending on the intent of the person compressing the data. I've heard MP3 files that squeezed double the amount of data into half as much space as a lossless file and they weren't half bad. Not half bad at all. Listenable, especially if you're not in the critical listening mode.
We'll look at some other file types tomorrow.