Symbolism is an important element of fiction that enhances a piece of literature. It is defined as a person or thing that suggests or represents more than its literal meaning. That is, the use of a noun to represent or imply something else of relevance. Symbolism is used strategically to evoke emotions or create ideas in the mind of the reader without explicitly stating them. There are two types of symbolism: conventional symbols and literary symbols.
Conventional symbols are those that are universal, or well-known. For example, the color red is universally representative of love or passion and crosses universally suggest religiousness. Conventional symbols are usually obvious or instantly recognized since they are common.
Literary Symbolism
Literary symbols are those that are established within a piece of literature through the content such as characters, dialogue, and settings. They are established through repetition and patterns. These symbols are usually obscured at first but become clear through literary analysis. Literary symbols are unlimited and can actually include conventional symbols as well.
Additional Resource: https://literarydevices.net/symbolism/