Symbols and motifs are literally devices commonly used by authors and artists in general. A symbol refers to objects, ideas, word, picture, or sound that is used to represent something.
It is basically used to prove something. Bear in mind that a symbol can become a motif. If a symbol is used repeatedly at several intervals in the literal work, it can be termed as a motif.
If it is used once within the literal work, it is unlikely to be a motif. Motifs, on the other hand, refer to an object, act, phrase, or sound used to make a theme. A motif often reoccurs and can be dominant throughout a literature work to make meaning.