What is the difference between an estimate and a quote?

What is the difference between an estimate and a quote?
Essentially, a quotation can be taken quite literally. An estimate, by definition, lacks certainty and can be subject to change depending on circumstances. A real example of the difference in commercial terms could be:
1. A quotation for the removal of an identified and quantifiable amount of rubbish to a destination that will accept it. Transported by a known means at a cost that can be identified = certainty.
2. An estimate for the clearance of a premises of an unknown quantity and type of rubbish and therefore potentially not accepted by a specific destination - for example, unexpected asbestos that requires specific and costly treatment - to destinations appropriate for their disposal at variable cost = estimate.

It would be unrealistic to expect anyone with any degree of understanding to provide a quotation in circumstances where the variables are unknown or beyond their control. Similarly, in defined circumstances it would be entirely reasonable to rely on a quote.

Anyone providing an estimate, or anyone accepting an estimate, should be familiar with the consequential variability and the very limited scope for enforcing the terms of an estimate. By contrast, one should be able to rely on a quotation and it will have far more gravity in the event of a dispute.

As always - Caveat Emptor. A Latin expression that perhaps has been applied differently over the centuries but is implicitly concerned with the caution a buyer should excercise in any transaction.