Resembles it’s referent. Something that looks like the thing in real life. This refers to it and is not a direct reference.
Associated with its referent.
Associated only by convention. For example the warning sign below. There is no actual danger in that image because it is only an image. We’ve culturally learnt that and it’s meaning.
An image that represents an object.
Represents a complete idea of concept.
An image that represents a sound. For example the IBM by Paul Rand.
A symbol that represents a sound of a letter.
Commentary and/or parody. A famous example of this would be Jonathan Branbrook.
Using well known symbols and submerging with a comical twist. This image is a personal favourite of mine as it shines a light on the use of alcohol and impotency and by using a unusual and phallic texture it portrays it into one image.
Pictoral. A picture that represents a company.
A logo compromised entirely of typography. These are some famous examples including NASA (The National Aeronautics and Space Administration) and Disney.