ما الفرق بين الحديث القدسي والقرآن؟

The Holy Quran is the miraculous word of Allah, revealed to Muhammad (peace be upon him), worshipped through its words, and prayer is not valid without it. Touching it is not permissible except for one who is ritually pure.

The Hadith Qudsi is what the Prophet (peace be upon him) narrates from his Lord. Its wording is most likely from the Prophet (peace be upon him), and it is not for worship or miraculousness. Its ruling is the same as that of the Prophetic Hadith in terms of authenticity and weakness, and both are revelations.