A pool is a small, still body of water. The dog in the picture is in a wading pool. Larger pools that are big enough to swim in are called swimming pools.
Sis forSwimming pool
A swimming pool is a place that people have made just for swimming in. They are usually made out of a hole dug in the ground, lined with concrete and tiled. Some swimming pools are above ground, or are inflatable so you have to pump them up with air before you fill them with water.
Swimming pools usually have very clear, pale blue water.
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A waterfall happens when a creek or river flows over a cliff. Waterfalls can be tiny, only a few inches high, or they can be many hundreds of metres high.
Waterfalls form when a river flows over rocks that are different hardness. The river will erode the softer rock faster than the harder rock, and over a long time a waterfall gradually appears.