A good question... 
It's called an ELLIPSIS
This Wiki piece sums it up pretty good
https://en.wikipedia.org/wiki/Ellipsis
In summary
An ellipsis (plural ellipses; from the Ancient Greek: ἔλλειψις, élleipsis, 'omission' or 'falling short') is a series of dots (typically three, such as "…") that usually indicates an intentional omission of a word, sentence, or whole section from a text without altering its original meaning.[1]
I've seen other meanings for it as well in modern usage.
I use them improperly all the time

It's called an ELLIPSIS
This Wiki piece sums it up pretty good
https://en.wikipedia.org/wiki/Ellipsis
In summary
An ellipsis (plural ellipses; from the Ancient Greek: ἔλλειψις, élleipsis, 'omission' or 'falling short') is a series of dots (typically three, such as "…") that usually indicates an intentional omission of a word, sentence, or whole section from a text without altering its original meaning.[1]
I've seen other meanings for it as well in modern usage.
I use them improperly all the time















