Final answer:
Composite volcanoes are tall, steep volcanoes made of both lava and volcanic material, while shield volcanoes are tall, gradually sloped volcanoes made mostly of lava flow.
Step-by-step explanation:
Tall, steep volcanoes made of both lava and volcanic material are called composite volcanoes. These types of volcanoes have a steep profile and are composed of alternating layers of lava and volcanic debris. They are also known for their explosive eruptions.
Tall, gradually sloped volcanoes made mostly of lava flow are called shield volcanoes. These volcanoes have a broad, low-profile shape and are built up by multiple layers of fluid lava flows. They are characterized by non-explosive eruptions.