Erosion is the removal of the products of weathering from where they were formed (the wearing away of rocks).
Transport is when weathered rock fragments fall away under gravity or are carried away by flowing water. 3 examples of transport agents are: water, wind and glaciers.
At slow speeds particles will fall to the bottom of the stream as sediment (this is deposition).
Largest particles are deposited first and then decrease in size. In this way particles are sorted according to size.
By studying sediment, scientists can tell a lot about where it came from and how it was carried: 1) Particle size - If its particles are similar sizes the sediment is well sorted. (Dust carried by wind is well sorted) If they are different sizes, the sediment is poorly sorted (poorly sorted sediment suggests an initial strong current which slows down suddenly. 2) Particle shape - A glacier cushions rock fragments and protects them from collisions so that they stay sharp and jagged. A fast flowing river flings rocks and stones against each other so they are smooth and rounded. The more vigorous the collision, the smoother the fragment. 3) The structure of the sediment.
If you threw a shovel full of soil sand and gravel into a very deep glass tank full of water, you would expect to see a sedimentary structure made up of different layers. The top layer would be the smallest and lightest particles such as sand and loom (silt). The lowest layers would be the heavier and larger particles such as pebbles and stones.