Foliage refers to the leaves collectively, as in "fall foliage," whereas the shoot system refers to the leaves, stem, flower, and fruit jointly.
A leaf is a vascular plant stem's main appendage, usually borne laterally aboveground and adapted for photosynthesis.
The entire set of leaves on trees that turn colour in the fall is an illustration of foliage. a decorative portrayal of leaves, stems, and flowers, particularly in architecture.