The knowledge of 'uloom al-Qur'aan, or 'The Sciences of the Qur'aan', deals with the knowledge of those sciences that have a direct bearing on the recitation, history, understanding and implementation of the Qur'aan. It is, therefore, a vast field of Islaamic scholarship, and one that is of primary importance.
Thus, for example, with regards to recitation, 'uloom al-Qur'aan deals with the science of pronunciation (tajweed), the different methodologies of reciting the Qur'aan (the qira'aat), the blessings of reciting the Qur'aan, and the etiquette of its recitation.
With regards to the history of the Qur'aan, 'uloom al-Qur'aan deals with the stages of revelation of the Qur'aan, the compilation of the Qur'aan, the art and history of writing the Qur'aanic script (rasm al-masaahif), and the preservation of the Qur'aan.
With regards to its understanding and implementation, 'uloom al-Qur'aan covers the causes of causes of revelation (asbaab an-nuzool), the knowledge of the makkee and madanee revelations, the knowledge of the various forms (ahruf) it was revealed in, the understanding of its abrogated rulings and verses (naasikh wal-mansookh), the knowledge of the various classifications of its verses (muhkam and mutashaabih, 'aam and khaas, mutlaq and muqayyad, etc.), the knowledge of the inimitable style of the Qur'aan (i'jaaz al-Qur'aan), the knowledge of its interpretation (tafseer), the grammatical analysis of the Qur'aan (i'raab al-Qur'aan) and the knowledge of those words whose usage has become uncommon over time (ghareeb al-Qur'aan).
It has been said that the knowledge of the 'uloom al-Qur'aan is in reality the knowledge that one is required to know in order to properly interpret the Qur'aan. Therefore, to call this branch of Islaamic knowledge 'The Procedure and Methodology of Interpretation' ('Ilm Usool at-Tafseer) instead of 'Uloom al-Qur'aan would not be far from the truth. 
However, 'uloom al-Qur'aan also includes topics that have very little or no bearing on tafseer, such as the compilation of the Qur'aan, and the development of the script of the Qur'aan. Therefore, the knowledge of 'uloom al-Qur'aan is more general than 'Ilm Usool at-Tafseer.  Notes:
 cf. ar-Roomee, Fahd ibn 'Abdur-Rahmaan ibn Sulaymaan: Dirasaat fi 'Uloom al-Qur'aan, Maktabah at-Tawbah, Riyadh, 1994, p. 33, who equates 'Uloom al-Qur'aan with Usool at-Tafseer.
 Shaykh Dr Abu 'Ammar Yasir Qadhi حفظه الله: An Introduction to the Sciences of the Qur'aan, Al-Hidaayah Publishing and Distribution, UK, 1999, pp. 18-19. See also: A Muslim's Obligation Toward the Qur'an