Salt marshes can protect coastal towns even when residents do not know every technical term used by ecologists. Dense plants slow incoming water, and their roots hold soil in place. Together, these features dissipate part of a wave's energy before it reaches buildings. A reader may not know dissipate, but the surrounding cause-and-effect pattern narrows its meaning: the plants make the wave's energy less concentrated or powerful. By contrast, the word before is essential because reversing the time relation would suggest that protection occurs only after the water reaches the buildings. The adjective dense adds useful detail about the plants, yet the central claim remains understandable without a precise measurement of density. Skilled reading does not mean ignoring unfamiliar words. It means deciding which words control the argument, which can be inferred from definitions or results, and which details can wait until the main relation is secure.