In technology, the word cache is a software or hardware memory component that stores data in order to quickly retrieve it for future use. It usually has a smaller capacity but is much quicker to retrieve information.
The word cache derives from the French verb "cacher", which means "to hide", so cache in noun form means a group of things that are hidden.
The correct pronunciation of cache both in French and in English can be written as cash. However, when you pronounce it in French the "a" is pronounced in a slightly more abbreviated way.
A common misconception of how cache is pronounced is that it is pronounced as ca-shei, but that is actually the pronunciation of another word: cachet, which means status or prestige.