In many cases these two terms are interchangable; whether it is correct to do so, or otherwise, is a moot point. Contracts based on British English may refer to a "Guarantee Period" following substantial completion of the Works, whereas one based on American English may refer to this as the "Warranty Period".

Generally, however, "warranty" relates to performance and/or obligations, usually by the Contractor.

A "guarantee" relates to the guarantor underwriting certain obligations, such as in a Bank or Parent Company Guarantee. I would note that the latter of these may not have any financial cost attached, so I suggest that defining the difference between ’warranty’ and ’guarantee’ based on costs is not always applicable.

Similarly,where a promise is intended, i.e., where a party warrants or guarantees to do or provide something, again these terms are generally interchangeable, based mainly on language.

Lo Gary,

It depends how it was express in the clauses of the contract. Basically both are the same.
Guarantee is more in manufacture while Warranty is more in distribution and reselling parts.
In construction Guarantee is more often use for defects and liability or probing period or complete replacement of the item/ article or product; usually valid for a fixed period of time while Warranty is more or less like insurance policy to pay certain amount to come into legal contract. Warranty covers only repair of the article.