"Carrots" are those crunchy orange vegetables Bugs Bunny is so fond of, but this spelling gets misused for the less familiar words which are pronounced the same but have very different meanings. Precious stones
like diamonds are weighed in carats.
The same word is used to express the proportion of pure gold in an alloy, though in this usage it is sometimes spelled "karat" (hence the abbreviation "20K gold").
A caret is a proofreader's mark showing where something needs to be inserted, shaped like a tiny pitched roof. It looks rather like a French circumflex, but is usually distinct from it on modern computer keyboards.
Carets are extensively used in computer programming. Just remember, if you can't eat it, it's not a carrot.