Condo associations may take upwards of 30 days to approve your application.  Most apartment communities can do it in the same day. 

Besides that, the differences are minor.  During the hayday of 2004 and 2005, many condo communities transitioned to apartments and many aparment communities went condo. 

Just remember, be wary of condo scams.  If you move in to a condo without being approved by the association, you can be evicted.  Many owners and even agents bypass the association hoping to not get caught, to move you in quicker and nab a quick buck.  Frankly, it's usually only the tenant who gets shafted.