When referring for example to the chats of these network of sites (Stack), which one is more appropiate: Chatroom vs Chatraum?
Chatraum is German, but it seems more popular the term chatroom (loanword).
Is correct to use both?
Just for clarification: Chatraum can be found in the Duden, so it is legit.
A very cursory Google search gave me quite a few hits, but as I see it, they are targeting a somewhat, hm, how should I put it … A slightly low-brow crowd which may be less familiar with English and technical terms than the average user.
I personally would choose Chatroom (capitalized!) in 99 % of all cases, except perhaps with a few elderly relatives because I’d have to translate only one word (ok, and the entire concept, but I digress). With a reasonably tech-savvy crowd, I highly recommend the full anglicism — if only to not be seen as part of the user group mentioned in the paragraph above.
In a colloquial context, you might as well abbreviate it as Chat, thus eliminating the dilemma altogether.
I never saw the term Chatraum being used by a reputable website. Websites designed for children tend to translate every anglicism and loanword into German. Thus rather weird terms like Chatraum can be found throughout the web.
So, in this example and probably in many others, you should stay with the English terms.