1. Weathering: This is the process of breaking down rocks, minerals, and other materials at the Earth's surface. Weathering can be physical (like frost wedging or abrasion) or chemical (like dissolution or oxidation). It creates the sediment that will eventually become sedimentary rock.

2. Lithification: This is the process by which loose sediment is transformed into solid rock. It involves several steps:

* Compaction: As layers of sediment accumulate, the weight of the overlying layers presses down on the lower layers, squeezing out water and air.

* Cementation: Dissolved minerals in the water that is squeezed out of the sediment precipitate between the sediment grains, acting like glue to bind them together.

So, in summary, weathering breaks down existing rocks into sediment, and lithification turns that sediment into solid sedimentary rock.