“Many writers profess great exactness in punctuation, who never yet made a point.”
— George Prentice —

ELLIPSIS

The omission from a sentence or other construction of one or more words understandable from the context that would complete or clarify the construction. A mark to indicate the omission of letters or words.

The ellipsis consists of three evenly spaced dots (periods) with spaces between the ellipsis and surrounding letters or other marks.

Let’s take the sentence, “The ceremony honored twelve brilliant athletes from the Caribbean who were visiting the U.S.” and leave out “from the Caribbean who were”:
The ceremony honored twelve brilliant athletes ... visiting the U.S.

If the omission comes after the end of a sentence, the ellipsis will be placed after the period, making a total of four dots.... Notice that there is no space between the period and the last character of the sentence.

The ellipsis can also be used to indicate a pause in the flow of a sentence and is especially useful in quoted speech:
Juan thought and thought ... and then thought some more.
“I’m wondering ...” Juan said, bemused.

Note the spacing of the ellipsis marks and the surrounding characters in the examples above. In mid-sentence, a space should appear between the first and last ellipsis marks and the surrounding letters. If a quotation is meant to trail off (as in Juan’s bemused thought), leave a space between the last letter and the first ellipsis mark but do not include a period with the ellipsis marks.

If words are left off at the end of a sentence, and that is all that is omitted, indicate the omission with ellipsis marks (preceded and followed by a space) and then indicate the end of the sentence with a period ... . If one or more sentences are omitted, end the sentence before the ellipsis with a period and then insert your ellipsis marks with a space on both sides. ... As in this example.

— Capital Community College Foundation
Guide to Grammar and Writing —