Who Knows What ... (dot dot dot) is called and the relevance of it's use ?

Cool Neville and yes I knew the answer...but the purpose of the question is to help others for it is always interesting to see the results... you did more research and that took time and effort yet hopefully it will help you in your own knowledge base apologies if trivial

Hi Trev. I'm wondering if you knew the answer before you asked ... But, thanks for the question anyway, since it gave me a chance to do a bit of online research. Oh, and by the way it also helped me complete today's Daily Mission.

Thanks Neville.. it is indeed called an ellipsis and in the use of todays free modern textual exchange the ellipsis is commonly used to continue in written word almost as a pause in a verbal deliverance from a speaker...the end only comes as a "stop" (.) in text or "silence" in verbal deliverance

Wikipedia says that (...) is called an ellipsis. The article on this at Wikipedia gives several examples of where it used, but basically it used to replace some omitted words and "used to indicate an unfinished thought or, at the end of a sentence, a trailing off into silence .....". The long article goes into much more detail.
Another use of these is in things like a Table of Contents, such as Chapter 1 ..........P 2, etc. In this instance the series of dots is called a Leader.

Thanks Ljerka for your great input... Carquote needs to do some more research (no offence intended)) the relevance of its use I believe would not apply in grammatically correct article structure...yet it does have relevance to textual comments or even blog posts and your comment Ljerka supports this and I quote "Or, you use it when you do not want to finish your thought and you let others to make their own conclusions" Do you know what it is called though ? this (...) combination

I know what it means but cant remember what it is called!

You use them whenever you want to stop summing ups and adding the same or similar things, ideas, items. Or, you use it when you do not want to finish your thought and you let others to make their own conclusions or you think that all that follows is quite obvious.
Relevance? I do not know - depends on the speaker ot writer, but I thinks you should not overuse it.

The shorter marks were called "dots", and the longer ones.