External Forces and Internal forces

1. These are forces which operate within the earth's crust.
2. Internal forces include volcanicity and earth movements, that is, horizontal (lateral) and vertical movements.
3. These forces may result in the formation of several landform features.

1. These natural forces operate on the earth's surface.
2. These forces mainly act on the earth's crust or close to the surface of the earth.
3. They include mountains, volcanoes, moraines, and valleys, just to mention a few.

The internal forces (tectonic forces) are divided into the following:

1. Earth movement (Diastrophism)
2. Volcanism/Volcanicity/Volcanic eruptions