Water is one of the most powerful forces on Earth when it is moving. It can create huge landforms such as the Grand Canyon and it can destroy landforms as it erodes them.
Erosion is the most obvious way that water can both create and destroy landforms. Water can eat away at an existing landform -- a plain or a cliff, say -- and make a new landform. Examples are the Grand Canyon or Bryce Canyon, both in the Southwest.
Through deposition, water can also create new landforms. These are typically in the form of flood plains and deltas.
Water can be very powerful when it is movingin a river the rocks and other particles will be eroded and then deposited somewhere else.another example: Rain will cause erosian by taking away soil, rock, and other particles on the land.Then with the land it has "taken" it will deposit it somewhere else creating new land.
For examples. Erosian-A farm feild has much fertile soil, after a hard rain some of the soil will be eroded and then deposted in the ditch. Or in the rainforest the soil doesn't have much nutrients in it because most of the soil erodes away. The biggest example would be the Grand Cnayon. that was all formed by the river eroding away the sides of the grand Canyon.
Weathering- River rocks are the biggest example because they have been smoothed down over thousands if not millions of year and then eventually just turn into sand.
Depostiation- All deltas are made from depositation.
As you can see erosian depositation and weathering are all in a big cycle and some of the terms overlap. i hope this helps!