Name
This Surah (Chapter) is named al-Fatihah because of its subject-matter. Fatihah is that which opens a subject or a book or any other thing. In other words, al-Fatihah is a sort of preface.

The Period of Revelation
It is one of the very earliest Revelations to the Holy Prophet. As a matter of fact, we learn from authentic Traditions that it was the first complete Surah (Chapter) which was revealed to Muhammad صلى الله عليه وسلم. Before this, only a few miscellaneous verses were revealed which form parts of 'Alaq, Muzzammil, Muddaththir, etc.

Theme

This Surah (Chapter) is in fact a prayer which Allah has taught to all those who want to make a study of His book. It has been placed at the very beginning of the book to teach this lesson to the reader: if you sincerely want to benefit from the Qur-an, you should offer this prayer to the Lord of the Universe.

This preface is meant to create a strong desire in the heart of the reader to seek guidance from the Lord of the Universe, Who alone can grant it. Thus al-Fatihah indirectly teaches that the best thing for a man is to pray for guidance to the straight path, to study the Qur-an with the mental attitude of a seeker- after-truth and to recognize the fact that the Lord of the Universe is the source of all knowledge. He should, therefore, begin the study of the Qur-an with a prayer to him for guidance.

From this theme, it becomes clear that the real relation between Al-Fatihah and the Qur-an is not that of an introduction to a book but that of a prayer and its answer. al-Fatihah is the prayer from the servant and the Qur-an is the answer from the Master to his prayer. The servant prays to Allah to show him guidance and the Master places the whole of the Qur-an before him in answer to his prayer, as if to say, "This is the Guidance you begged from Me."