Imagery is defined as any type of description that relates to a person's five senses. Technically, however, there are seven types of specific imagery related to our senses:
- Visual: related to things that may be seen
- Auditory: related to things that may be heard
- Olfactory: related to things that may be smelled
- Gustatory: related to things that may be tasted
- Tactile: related to things that may be touched (with the hand or some other body part)
- Kinesthetic: related to motion and/or movement
- Organic: related to feelings inside the body (i.e. hunger, emotions)
Symbolism refers to things that represent other ideas. For example, a white lamb in a poem may be a symbol for innocence.
So, although there might be symbols used in descriptive images, the two terms are not interchangeable.
Imagery is a term used when referring to any descriptive language used by a writer. When you see something in real life, or in a photo or a film, you see an image. When you read a description of something a writer wants you to visualize (or sense in some other way), he/she must use imagery to get the picture across to the reader.
Symbolism is one thing that stands in for or represents another. Colors are common symbols in literature: white for purity, virginity or cleanliness; red for passion, anger or evil. Usually a color or other object needs to be repeated in order for the reader to understand that the writer intends it to be symbolic.
Imagery is the formation of mental images, figures, or likenesses of things, or of such images collectively: the dim imagery of a dream.
Symbolism is the practice of representing things by symbols, or of investing things with a symbolic meaning or character.