'guarantee' vs 'warranty'

I think they mean the same thing, in everyday use.
There may be a fine legal difference, but I don't know about that.
But a guarantee, is a warranty, same thing.

In British consumer-law usage the difference is this:

Guarantee

A guarantee is usually free and is a promise about an item by the manufacturer or company

It's a promise to sort out any problems with a product or service within a specific, fixed period of time

Whether you paid for a guarantee or not, it is legally binding

The guarantee must explain how you would make a claim in a way that is easy to understand

It adds to your rights under consumer law

It will take effect whether or not you have a warranty

Warranty

A warranty acts like an insurance policy for which you must pay a premium - sometimes a warranty is called an 'extended guarantee'

May last longer than a guarantee and cover a wider range of problems

A warranty is a legal contract

The terms of the contract should be clear and fair

Does not reduce your rights under consumer law

A warranty can be in place with a guarantee