While I might refrain from using wikipedia as a source in most cases, it provides the most complete definition of the phrase in question.

Wikipedia defines a "Still Life" as "a work of art depicting inanimate subject matter, typically commonplace objects which may be either natural (food, plants and natural substances like rocks) or man-made (drinking glasses, cigarettes, pipes, hotdogs and so on) in an artificial setting."

Perhaps some of the confusion comes from the deviantART Gallery description for still life, "Still life showcases studio-style photography that features inanimate objects," though even with it's limited description, it remains clear enough that it should not be misunderstood as long as it is read. But back to the main point.

Still life focuses not on freezing active life, making it still (that falls in the realm of portraiture, or nature photography focusing on animals and plants, or landscape), but rather capturing constructed scenes of already still objects.

While this is a practice that has been understood and performed since the mid 1600's in renaissance painting, it has seamlessly carried over to the photographic medium.

The practice of still life is perhaps just as complicating as mastering any of the artistic mediums themselves. It is a practice that, instead of always capturing what is around us, relies on building our own successful compositions, to a point where the construction may become an art form of its own.

Below are some selections from both a more traditional style of still life, and from a more contemporary approach.