Beach waves are formed when wind blows across the surface of the ocean, creating ripples that grow into larger waves. These waves travel across the water until they reach the shore, where they break and crash onto the sand. The size and shape of the waves can vary depending on factors like wind speed, water depth, and the coastline's features. When waves break on the beach, they create a foamy white crest and can produce sounds like crashing or roaring. The energy from the waves can also shape the beach over time, moving sand and creating features like sandbars and dunes.