Shield volcanoes grow as relatively fluid lava spreads in repeated flows. Their broad, gently inclined flanks are the key clue; Mauna Loa forms the distant skyline in this photograph, beyond Kīlauea’s caldera.
Start with width rather than a dramatic summit. Small cones or depressions can sit on a shield without changing its overall form. This is a useful first comparison with a composite volcano: the entire profile matters more than any one bump.
Source / photo: NPS / David Boyle · Public domain. Resized. No claim to original U.S. Government works.