Internal Factors :
earthquake and volcanic eruptions that originates under the earth surface. They are active beneath earth surface and causes changes in the crust of earth surface. They can bring changes in short period of time because of their abrupt nature .
External Factors:
Rivers , glacial current waves, rainfall , living beings ,etc are some of the examples that can bring changes on earth surface. It appears after a period of time with erosion , transportation and deposition processes. due to these effects landforms changes into plates ,U and I valley,small hills etc.
