What a freight rate and a freight quote are
A freight rate is the price to move a shipment from one place to another. A freight quote is a provider's offer to move a specific shipment, on a specific date, for that rate. Some quotes are spot quotes for a single load at today's market price. Others come from contract rates agreed in advance for regular lanes.
Either way, a quote is only as accurate as the description behind it. If the weight, size or delivery site turns out different, the price can change.