Icon is not an abbreviation or initialism. An icon, in the historical sense, was an object used to represent something else, usually a god or spirit. In today's usage, an icon is a representation of a program or file in a GUI (graphical user interface).
Icon
A file, folder, or program =P
The dog head icon represents loyalty and protection in this context.
"ico" is a common extension for an icon. An icon is the image you see in a file browser or on your desktop. That icon will represent a file.
icon
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ICON
an icon
Icon is a picture that represent a computer object or feature.
The presidents represent a national icon of the United States.
icon
an icon