An ellipses (the plural form) is three spaced ellipsis (singular) points. In print, they are . . . space-dot-space-dot-space-dot-space.
For ellipses in your manuscript, you should follow the guideline for submissions of whomever you submit to, but don’t assume a processor’s auto select for the three dots will be universally accepted. Having sternly warned you, I’ll have to admit no agent or publisher will reject a manuscript if ellipses are presented in a consistent manner.
What are ellipses for?
In academic and journalistic prose, ellipses are to signal a missing word or words.
In novels, smart writers realize commas cannot be used to force pauses and hesitations, so more and more we see ellipses used to represent lapses in speech.
Ellipses in dialog are great. However, too many ellipses in the wrong places for the wrong reasons can most certainly add to grounds for rejection of manuscripts. I’ve seen too many third-person manuscripts where paragraph after paragraph of narrative trails off in ellipsis points, as if the narrator wants to say more but can’t . . . or won’t. Even in first person narration, ellipses should be used sparingly or not at all. As Aristotle advised . . . Moderation in all things.