icons, symbols, indexes

Icons are signs whose signifier bears a close resemblance to the thing to which they refer

Icons are said to be motivated

Iconic signs have a marked physical or perceptual resemblance between the signifier and that to which they refer

Words are symbolic signs

There is no natural relationship between the word and its meaning, it's abitary and meanings are arrived at by a cultural convention.

Pierce used the word symbol to refer to a category of sign when there is no resemblance between it and its object.

Indexes lie somewhere in between icons and symbols. An index is a sign whose signifier we have learnt to identify with a particulare signified.

An index is connected to its object.

e.g. smoke is an index of fire

Icons, symbols and indexes are INTERACTIVE and OVERLAPPING