What are the differences between alluvial, eluvial and colluvial deposits?
Your question is almost a duplicate of What is the difference between eluvium and alluvium?, but you also ask about colluvial deposits. The accepted answer for that question references this convenient guide from the Australian Museum, which also covers colluvial deposits:

Alluvial: Detrital material which is transported by a river and usually deposited along the river's pathway, either in the riverbed itself or on its floodplain.
Colluvial: Weathered material transported by gravity action such as on scree slopes.
Eluvial: Weathered material still at or near its point of formation.