What is the difference between weathering and erosion?

Weathering is the physical or chemical break down of rock or soil in the place where the rock/soil is located - called 'in situ'. No material is transported when an in situ rock is weathered, however its shape may change! Erosion is the transport of this weathered material, usually by wind, water or ice.
Weathering occurs in place, whereas erosion involves the transport of material. However, these processes often happen at the same time and can be caused by similar factors such as wind, ice, temperate, water or biological action.