difference between FIX "Market Data Request" & "Quote Request"

Hi Yuval,

Sorry if my question was not clear, I’m trying to ask if there is another way (instead messages V, W, X) to send orders that already exist in the market to a user that is connecting. Because I read the article: http://www.fixtradingcommunity.org/mod/file/view.php?file_guid=42854
and Currently I’m using NewSingleOrder(D) message to enter orders and MarketDataRequest, MarketDataSnapshotFullRefresh and MarketDataIncrementalRefresh. But someone who also read the article said: Why we are not using the methodology Quotes, this seems to avoid the use of the MarketData… messages.

I hope now is clearer and you can explain something more.

Thanks.
Benito.