Strata is a term used to describe sedimentary rock LAYERS. It is derived from the Latin word for 'LAYERS' and is used to refer to the LAYERS of sedimentary rocks that are formed over time due to the accumulation of sediments. These LAYERS can be seen in many geological formations, such as mountains, valleys, and canyons. STRATA can also be used to study the history of the Earth, as the different LAYERS can provide information about the environment and climate at the time they were formed.