"A [Metadata] tag is a non-hierarchical keyword or term assigned to a piece of information (such as an internet bookmark, digital image, or computer file). This kind of metadata helps describes an item and allows it to be found again by browsing or searching. Tags are chosen informally and personally by the item's creator or by its viewer, depending on the system. On a website where many users tag many items, this collection of tags becomes a folksonomy." - (Wikipedia)
My Delicious Tag Cloud, by Wordle:
Q: Don't like the dark background and the light text colors on this page?
A: See Dark to light, light to dark, here for how to flip them.