Erosion can be described as follows: Erosion refers to the gradual removal or wearing away of the Earth's surface by various natural agents. These agents, which include water, wind, ice, and gravity, transport eroded material from one place to another. As the eroded material is moved, it can be deposited in new locations, leading to the formation of distinct landforms across the Earth's surface. The process of erosion and deposition shapes the landscape in diverse ways, creating a variety of landforms such as valleys, canyons, deltas, beaches, and sand dunes. For example, water erosion can carve out channels and valleys over time, while wind erosion can shape sand dunes and rocky outcrops. Overall, erosion and deposition are dynamic processes that continuously reshape the Earth's surface, contributing to the formation of diverse and visually striking landforms that define the geography of our planet.

Sand dunes can be described as follows: Sand dunes are mainly found in deserts or beaches. They are formed due the activity of wind. When the wind blows, it lifts and transports sand from one place to another. When it stops blowing, the sand falls and gets deposited in low hill-like structures, typically taking the form of mounds or ridges, which are called sand dunes.