Rocks formed from weathered debris of pre-existing rocks are called sedimentary rocks.

Here's a breakdown:

* Weathering: The process of breaking down rocks into smaller pieces (sediments) through physical or chemical means.

* Erosion: The movement of these sediments by wind, water, or ice.

* Deposition: When the sediments settle and accumulate in a new location.

* Lithification: The process of turning loose sediments into solid rock through compaction and cementation.

So, sedimentary rocks are essentially formed from the "leftovers" of older rocks that have been broken down, transported, and then cemented back together.