Same concept. You're just using a larger bait pile.
Yes and no. Habitat improvment don't fall into a traditional bait catagory IMHO. They will alter deer movement but it is a natural benifical dietary supplement where as bait is placed out for the sole purpose to attract deer. Food plots will attract deer and other wildlife because it offres quality forage that may not already be available in the area but the deer will benefit from the plots.
I will clearly state that I do not condone hunting over a plot. But a plot is a great tool in an overall managment plan to increase deer populations and herd quality.