And, I would also add to this, regarding tajweed, that those who learn tajweed (correct articulation of letters and pronounciation - there are specific rules for the Qur'an that are not for ordinary Arabic text) and are qualified in tajweed (have a qualification known as an ijaazah), have a known chain going back to Allah. Not everyone who learns tajweed has an ijaazah.
To obtain an ijaazah, you must learn from a teacher who has an ijaazah, their teacher must have had an ijaazah, and so on.
An ijaazah requires reciting the whole complete Qur'an to someone with an ijaazah, with complete tajweed and excellent memorisation. To obtain an ijaazah is a great achievement, and honour from Allah. Upon getting the ijaazah, the haafith (memoriser of Qur'an) who has the ijaazah is now certified and approved to transmit the Qur'an and it's tajweed to others with the big responsibility of transmitting it as the Prophet (peace be upon him) recited it, with every single letter articulated from the correct point in the mouth/throat, and every word pronounced correctly.