I think the primary difference is that in Commercial properties, lenders are more interested in the Cash flow and potential upside when deciding to finance and not little emphasis on buyers individual credit worthiness or cash in bank. ( Don't get me wrong, he/she still needs to show 30% down payment but that is not necessarily his/her personal income).
Flip that to the residential side - Owner credit worthiness is the most important criteria and the residential asset is secondary. If you are able to get a million $ property for 600K, bank is not going to lend if you do not have the 120K ( 20%) in bank.
On the sell side again, you could have a really great commercial asset in a not so great location and you can expect top $if you want to sell. Residential on the other hand is tied to the location and if the location is depressed, your home price will be depressed as well.
This is the basic difference. If you get this, then you can talk about advanced concepts like Tax advantages, Depreciation, etc.
Hope this helps.