Going Tidal, Need ???

I plan to subscribe to the Hi-Rez Tidal service at $20/month.
In addition I have been told to expect to pay $150/year for
the Roon Service. Apparently Roon’s software is said be easiest to navigate.

So what equipment do I need to buy to enjoy HiRes sound?
-I do not have a lot of downloaded material, cds or records to store.
-I do have a DAC built into my cd player-oppo 205-which is usable independently.
-Budget is $2,000.00

Can someone explain to me, using 50 or less and small words, how streaming hardware and software function?
Equipment I own: Freya/Cary/Oppo/Altec. 

Thanks,

Jeff