What is the significance of the three dots “…” on menus and buttons and how to use them right?

Adding three dots after the title of items in a dropdown menu seems to be a common practice (as you can see on the picture of a drop down menu in Google Chrome). They generaly mean that there is “something” after clicking on it.

Google chrome dropdown menu (french version)

These dots are also sometimes presents in the text of action links and buttons.

I am wondering about their utility and relevancy…

In your opinion :

  • What kind of information should be conveyed by these dots ?
  • How and when to use them ?
  • Is it realy relevant to the user, and easily understood by them ?