[11-12 of 44 commonly confused words]
People sometimes use cachet when cache is required. Despite having five letters in common, and coming ultimately from the same French verb (cacher), in English they are completely unrelated. A cache of something is a “collection of items of the same type stored in a hidden place” such as an arms cache or a cache of gold and rhymes with cash.
Cachet is “prestige, high status; the quality of being respected or admired” and rhymes with sachet. The next two examples show the words being used correctly:
Several inmates seized a cache of grenades and other weapons and killed six security officers, including a high-ranking counterterrorism official;
The department stores knew they had to offer something different, something perceived to have more cachet.
In the next one, cachet is wrong, and cache would be correct: Egyptian excavators this week chanced upon a cachet of limestone reliefs.