Why are there different recitations of the Quran?

Where the differences come from

Umar once heard Hisham ibn Hakim reciting Surah al-Furqan in a way he had not been taught, and he took him to the Prophet ﷺ. The Prophet ﷺ asked each of them to recite and said of both: "It was revealed in this way." He then added: "This Qur'an has been revealed to be recited in seven different ways, so recite of it whichever way is easier for you" (Sahih al-Bukhari 4992). In another report he said Jibril kept reciting in more ways at his request until he reached seven (Sahih al-Bukhari 4991).

This was a mercy to people who spoke different Arabic dialects. Scholars have different explanations of exactly what these "seven ways" (ahruf) were, and they are not the same thing as the seven or ten famous qira'at that exist today.

What the qira'at are

The qira'at are the recognised ways of reciting the Quran that have an unbroken chain of narration back to the Prophet ﷺ and fit the written text. Ten are widely accepted by scholars, each named after a reciter such as Nafi', Asim or Abu Amr, and each with its own narrators. For example, Hafs and Shu'bah both narrate from Asim.

What kinds of differences are there?

• Pronunciation: how a letter is said, a vowel is lengthened, or a hamzah is handled.
• Vowels: a different vowel on a word, which can slightly affect the meaning.
• Occasional wording: a word that is read in different forms, such as with or without a long vowel.

For example, in Surah al-Fatiha some readings have "Maalik" (Master or Owner) and others "Malik" (King) in this verse:

Both meanings are true of Allah, so the readings add to each other rather than conflict.

Which one do I use?

Most of the world recites and prints the Quran in the reading of Hafs from Asim, including the widely used Madinah Quran. Other readings are common elsewhere, for example Warsh from Nafi' in parts of North and West Africa. As a learner, recite the one your teacher and community use, and don't mix readings in the same recitation.

The differences are also not a sign that the text was altered. After disputes about recitation arose in the armies, Uthman had the Quran copied from the original manuscripts into standard copies, so that the community would not differ about the Book (Sahih al-Bukhari 4987). See Was the Quran changed over time? See Is the Quran the same in every country?

If you are starting with tajweed, just learn the one reading your teacher gives you. See What is tajweed and do I need to learn it?