The outermost layer of the Earth is called the crust. This layer consists of a thin, solid shell that forms the Earth's surface and is composed of a variety of rocks and minerals. The crust is relatively light compared to the underlying mantle and is divided into continental and oceanic types. The Earth's crust plays a vital role in geological processes like plate tectonics, and it supports ecosystems and human life by providing resources such as minerals, soil, and fossil fuels.