What are symbols and instances in Flash?

In Flash, symbols are reusable graphic elements that can be created and manipulated within the application, such as buttons, movie clips, and graphics. They allow for efficient design and animation by enabling repeated use without duplicating the original asset. Instances, on the other hand, are specific occurrences of a symbol placed on the stage; each instance can have its own properties and behaviors while still retaining the link to the original symbol. This structure helps streamline the workflow and maintain consistency across projects.