Describe how the underlying array of a slice can affect the slice's behavior.

The underlying array of a slice significantly impacts its behavior. A slice is essentially a window or view into an array. If the underlying array's size is exceeded, a new array with a larger size will be created, and the slice will be updated to reference it. This can lead to performance and memory implications if not managed properly. Additionally, sharing the underlying array between slices can cause unintended side effects. Understanding this relationship is crucial for efficient slice usage.