Request for bid -- During the time of bidding the vendor will be selected solely based on the price quoted for the work mentioned in the procurement statement of work for example if there is a tender for constructing bridge the seller who quotes the lowest price will be selected. Request for Bid is a Fixed type Contract
Request for proposal -- Here the buyer is requesting for price and detailed proposal
Request for bid -- During
Request for bid -- During the time of bidding the vendor will be selected solely based on the price quoted for the work mentioned in the procurement statement of work for example if there is a tender for constructing bridge the seller who quotes the lowest price will be selected. Request for Bid is a Fixed type Contract
Request for proposal -- Here the buyer is requesting for price and detailed proposal
Request for bid - proposal
RFQ vs RFB vs RFP
Here is some info, i found on net:
http://purchasing.ucsc.edu/howto/quotes&bids.html