Final answer:
A rock formed by the cementing of weathered particles of pre-existing rocks is called a sedimentary rock, which is different from igneous rocks (formed from cooled molten material) and metamorphic rocks (altered by heat and pressure).
Step-by-step explanation:
A rock formed from the weathered products of pre-existing rocks is called a sedimentary rock. These rocks are typically created when small particles or sediments, resulting from the weathering and erosion of existing rocks, are cemented together over time.
Sedimentary rocks also include materials precipitated from solution or the accumulation of organic materials, like the shells of living organisms. In contrast, igneous rocks are formed from the solidification of molten magma or lava, and metamorphic rocks are created when existing rocks are transformed by heat and pressure beneath the Earth's surface.