Not fundamentally different than normal, wind-driven waves: disturbances that moves through water. Origin and magnitude are different: wavelength: from one crest to the next, wave height: from crest to trough, motion decreases as you go deeper, wave base: negligible water motion below wavelength. Very long wavelength waves: strike bottom much further offshore, climb to larger heights. Wave created by disturbance in the water. Begin to crest when the wave base intersects the ocean bottom: waves slow down, subsequent waves catch up. Unrelated to tidal movements of ocean water: why the confusion. Incoming tides at funnel-shaped bays: tidal bores. Time between successive wave crest: can be observed on tide gauges. Run-up: maximum elevation reached: debris or vegetation loss, maximum height in land. Inundation level: distance inland: how far inland. Tsunami are waves that differ from normal surface waves in no fundamental way. Function of water depth (d) and gravitational acceleration (g: velocity= (gd)^1/2.