An icon (from Ancient Greek εἰκών (eikṓn) 'image, resemblance') is a religious work of art, most commonly a painting, in the cultures of the Eastern Orthodox, Oriental Orthodox, and Catholic churches.

In cultures

A cultural icon is a person or an artifact that is identified by members of a culture as representative of that culture.

e.g. Mount Fuji for Japan, Red Telephone Box for Britain, Apple Pies for USA, Matryoshka Dolls for Russia (alongside USSR, Hammer and Sickle and Vladimir Lenin)

Religious icons can become cultural icons, if the religion is deeply ingrained to the culture.

In computing

An icon is a pictogram or ideogram displayed on a computer screen in order to help the user navigate a computer system.

The computing definition of "icon" can include three distinct semiotical elements:

Icon (Direct Resemblance to the Referent)
- e.g. printers, scissors, file cabinets, folders, etc.
Index (Associated to the Referent)
- e.g. stylized drawings used to refer to actions, like "printer" for "print", "scissors" for "cut", "magnifying glass" for "search", etc.
Symbol, which is related to its referent only by convention (letters, musical notation, mathematical operators etc.)
- e.g. Standard symbols such as power on / off, USB icon, etc.

The majority of icons are encoded and decoded using the following figures of speech:

Metonymy (A figure of speech in which a concept is referred to by the name of something closely associated with that thing or concept)
- e.g. "chicken" refers to the "bird" and the "meat"
Synecdoche (A type of metonymy; it is a figure of speech in which a term for a part of something is used to refer to the whole (pars pro toto), or vice versa (totum pro parte). The term is derived from Ancient Greek συνεκδοχή (sunekdokhḗ), meaning 'simultaneous understanding')
- e.g. "suits" for "businessmen", "wheels" for "automobile", and "boots" for "soldiers"
Metaphor (A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are usually meant to create a likeness or an analogy.)
- e.g.
  
  "All the world's a stage,
  And all the men and women merely players;
  They have their exits and their entrances
  And one man in his time plays many parts,
  His Acts being seven ages. At first, the infant..."
  —William Shakespeare, As You Like It, 2/7

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