Commercail vs DSLR?

[therock003]

Can someone guide me into understanding the differences between an everyday commercial digital camera and a DSLR? What is the reason for prefering a DSLR over a commercial camera?

 

[lordsmurf]

What is a "commercial camera" supposed to mean?
Do you refer to film? Or maybe medium format or large format digital?
Question doesn't make any sense.