Weathering is the breaking down of rocks with water creeping through the cracks of mountains or boulders and breaking them down into small rocks called sediments. Here is an example of weathering:

Erosion is the action of water, wind, or human activity moving soil and rock from one location to another. Here is an example of erosion:

Deposition is the settling down of sediments and/or soil in one location to form a different landform. Here is an example of deposition: