This little sucker is known as an ellipsis. It can be used for a few different reasons, and it can be improperly used like mad.
You know... I'm sure you can understand... how it can be increasingly annoying... to read an email... or a manuscript... that uses dot... dot... dot... improperly and abundantly.
I'll be the first to admit, there are times that I do the dot-dot-dot in my silly blog posts, but to overuse (and improperly overuse) this device has grown to become one of my biggest pet peeves, right up there with mispronouncing or misusing big words because the speaker is trying to impress with vocabulary.
This handy little booger can be used when you are omitting words from quoted material. (But be sure not to change the meaning of the material) For example:
T. Michelle Nelson is a native of Benton, Kentucky, a graduate of Murray State University and she currently she resides in picturesque Mount Vernon, Ohio.
T. Michelle Nelson is a native of Benton, Kentucky... and she currently she resides in picturesque Mount Vernon, Ohio.
It can also be used to show a pause or break in speech. This is where they get so dang annoying. Every time you have a break in thought, this doesn't mean you can throw out all other forms of punctuation. In fact, it's quite easier to type one period instead of three.