Here's why:

* Formation: Sedimentary rocks are formed from the accumulation and cementation of sediments like sand, mud, or organic matter. These sediments are often deposited in layers over time, creating the distinct patterns we see.

* Examples: Common examples of sedimentary rocks with layering include sandstone, limestone, shale, and conglomerate.

While some metamorphic and igneous rocks can exhibit banding, it's not the same as the distinct layering seen in sedimentary rocks.