Is the Qur’an preserved in both wording and meaning, or in meaning only, and what is the reason for the variation of some words between narrations?

Memorizing the Quran includes its wording, performance, and pronunciation, as it has reached us through an unbroken chain of transmission (tawatur) from the Prophet, peace and blessings be upon him, and his companions. The variation in some words within it is due to its revelation in seven ahruf (modes of recitation), as a facilitation and mercy for the Ummah. This variation is one of diversity and complementarity, not one of opposition or contradiction, and it reveals aspects of its miraculousness and the comprehensiveness of its meanings.