Is it better to place text above or below icons?

1. Should text go above or below image?
2. Why use icons instead of text?

Should text go above or below image?

Text that serves as the description of an image should always go below the image, because it is a description of the image, meaning the image is the source of context.

Why use icons instead of text?

Icons can save space over text, but at the price of recognition. For small icons, such as 16x16 pixel, it's very difficult for users to even recognize what they are supposed to be a picture of, let alone what the picture is supposed to stand for. One user I know thought the “disk” icon for save was a picture of a TV.