Educate me about DSD

So I don't know very much about DSD audio and files. I keep hearing it's good. I am a digital guy, streaming Tidal, Quobuz and still playing cds.

But I bought a streamer capable of DSD 512, therefore I want yo lean more. Can these files be streamed? Say on Tidal or another streaming service? Do I need to buy DSD discs? What does the audio qualities sound like? I assume much better than CD.

What can you tell me about DSD?