When you have done good things and people knows about you, they will treat you with respect and their tone/body language reflects that.
And when they do not know you but still want to be civil about it, they will be courteous. And that is the difference.
I experienced this when I was at one of the customer's place yesterday. Both of us were engaged by the same reseller. So, this guy lays the cables and I terminate and program the extensions. And he is getting on, to the age where he should be enjoying fishing some where or reading papers and drinking his kopi-o.
It was in this incident which embarassed me. You see, he called me "sifu".
However, this is not because I have Martial Art skills or whatever skills which he thinks I am master of. But he did this due to courtesy and nothing else. In a way, he wants to talk to me but does not know my name (and vice nersa) so, to save both our faces, he address me as such. And I am a bit unconfortable because I am years younger than him, which IMHO, I should be giving him the title instead.
Nowadays, in this industry, I think, the title "Sifu" is now used to courteously address a person of his trade/skills when a site. Its much better then the usual, "Hey", or ".. so you do this and that..", "Ey, SinSang (Chinese for Mister)", "Lou sai" (As in Yo! Boss!) and even "Tailo, ah (in a sarcastic/friendly tone, depending on situation)
And I kept calling him Mister. Haih.