The purpose of the SAMPLE&HOLD module is to "freeze" the input voltage with a trigger input.
Typically used for random CV patterns if a noise signal is fed to the input and triggered e.g. by an LFO.
You can find more information about this module on the AE Modular Wiki.
(Price without VAT; for buyers inside the EU 19% VAT will be added to the shown price = 33,32€)