Stubs are entries that have not yet received substantial attention from the editors of the Wiki, and as such do not yet contain enough information to be considered real articles. In other words, they are short or insufficient of information and require additions to further increase the Wiki's usefulness. The community values stubs as useful first steps toward complete articles.
A stub is an article that's obviously too short, but not so short as to be useless. In general, it must be long enough to at least define the article's title, which generally means 3 to 10 short sentences. Note that even a longer article on a complicated topic may be a stub; conversely, a short article on a topic of narrow scope may not be a stub.
Another way to define a stub is an article so incomplete that an editor who knows little or nothing about the topic could improve its content after a superficial internet search or a few minutes in a reference library. An article that can be improved by only a rather knowledgeable editor, or after significant research, may not be a stub.
Once a stub has been properly expanded and becomes an article rather than just a stub, you or any editor may remove the stub tag from it. No admin action or formal permission is needed.