Here's a breakdown of how it forms:

* Sediments: These are tiny pieces of rock, minerals, or organic matter (like shells or plant fragments) that have been weathered and eroded from other rocks.

* Buried and Compressed: Over time, these sediments accumulate in layers and are buried deeper and deeper. The weight of the overlying layers compresses the sediments.

* Cementation: Dissolved minerals in groundwater seep through the sediment layers. As the water evaporates, the minerals crystallize and act like glue, binding the sediment particles together.

This process of sediment accumulation, compression, and cementation creates sedimentary rocks. There are many different types of sedimentary rocks, each with unique characteristics depending on the type of sediment and the cementing minerals involved.