Here are a few links that will probably provide a much better basic overview than I ever could.
https://roonlabs.com/howroonworks.html
https://kb.roonlabs.com/Sound_Quality
https://roonlabs.com/
I listen to music almost every day so I don't mind paying $10 a month for the convenience, user experience and sound quality it provides. Likewise, I'm OK with paying $20 a month for Tidal Hi-Fi. The amount of high quality new music that I'm exposed to and have at my fingertips for the price of a CD or two a month is priceless. The fact that Roon & Tidal integrate so well together is a major plus.
Roon ties your entire digital music library (physical or streamed) together seamlessly, and does a wonderful job of not getting in the way (or if you want it can with parametric eq, upsampling, converting etc.), allowing for the best possible sound quality your files and system can reproduce.
I'm not saying it's for everyone but it works for me.
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