Jhoira of the Ghitu Avatar is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

, Discard a card: Copy three instant cards chosen at random. You may cast one of the copies without paying its mana cost. , Discard a card: Copy three sorcery cards chosen at random. You may cast one of the copies without paying its mana cost. Activate only as a sorcery.