That info is pretty much easily available with a Google search:
The warranty time as stated by European regulation means that during the first 6 months the seller has to prove that the device was not defective upon arival. Since that is pretty much impossible, the law assumes that if the device breaks during this time, it was already defective from the very start.
In the period after the first 6 months, you as a buyer have to prove that the device was defective from the start and that it is not you who is responsible.
Furthermore, that 24 month warranty is part of the contract between you ,the buyer, and the seller (the shop you got it from).
The guarantee on the other hand is a voluntary offer by the manufacturer, and therefore this is an arrangement between the buyer and the manufacturer (who might just delegate all the beaurocracy to the seller).
Those things are really very different.
Please note that I am not a lawyer, and neither is English my native language. So take the above with a grain of salt.