Yes thats correctWith what I understand of iray, it is just a server application and some clients if using multiple pcs. the "iray server network" as such is YOUR network. This IS for rendering "in house".
you install the server application and a client application on your workstation (or only the server if you don't want to render on that machine as well) and use 1 or more additional pcs which basically just have an operating system - windows or linux in this case, probably even mixed - and the render client installed. you then control the render jobs from the machine with the server running on it and the others do literally nothing except rendering.
this would probably also enable you to work on your images and animations on the pc with the server while 3 other pcs with only the client keep happily rendering. of course i don't know how your workflow is right now, but i'd think maybe you would be posing stuff OR rendering stuff, not both at the same time?
i also didn't look into the minutiae of iray, but i'd expect it to be able to start and stop specific clients on a button press so you could probably do something like "have it render on all machines while i'm afk, stop rendering on the main workstation while i'm working on it, keep the other machines rendering all the time" or something like that.
since it's a software made by nvidia as far as i understand, it might even be more performant than using daz itself. or make better use of the gpu hardware or whatever.
i might have to try that one myself... sounds interesting. too bad i don't really have anything to render... and my best nvidia card is a 4060... eh... maybe 3d print models...
It's an "inhouse" solution with your own machines
I use it with my old GTX1070 and a Ryzen 2600 as an iray server - for "small" renders
My MainPC has a RTX4070ti - for the "bigger" ones