What is the difference between physiography & topography? I can't understand the context in which to use both. Please explain by giving suitable examples.
Physiography explains the physical characteristics of the area more generally describing the physical processes or forces that formed the landscape, while topography describes particular features, typically associated with elevations. For example in geomorphology (as your post is tagged) the physiography of Canadian prairies may describe deep fertile soils, ancient lake bed remnants, multiple sloughs or ditches that fill with water, etc. The topography would describe the extreme flatness with many depressions in the landscape. In practice, physiography is quite broad and topography refers to elevation data (I.e. a topographic map would have elevation points or contours).
Take a look here at WikiDiff as well.