People of the Book (Arabic: أهل الكتاب ′Ahl al-Kitāb) is a term used to designate non-Muslim adherents to faiths which have a book of prayer. The two faiths that are mentioned in the Qur'an as people of the book are Judaism and Christianity. However, Muslim rulers and scholars have included other religions such as Zoroastrianism and Hinduism in this list as well. 
In Islam, the Muslim scripture, the Qur'an, is taken to represent the completion of these scriptures, and to synthesize them as God's true, final, and eternal message to humanity. Because the People of the Book recognize the God of Abraham as the one and only god, as do Muslims, and they practice revealed faiths based on divine ordinances, tolerance and autonomy is accorded to them in societies governed by sharia (Islamic divine law).
In Judaism the term "People of the Book" (Hebrew: עם הספר, Am HaSefer) subsequently became self-applied to refer specifically to the Jewish people and the Torah; also the Jewish people and the wider canon of written Jewish law (including the Mishnah and the Talmud). In the Jewish tradition's use of the term there is generally no connotation as to the nature of Judaism's relationship with other faiths.
Many early Islamic scholars, such as Malik ibn Anas, agreed that Zoroastrians should also be included. Zoroastrianism is believed by scholars and historians to have been founded between 1000 BCE and 600 BCE making it older than Christianity and Islam. It shares similar eschatological views with Christianity and Islam, and recognizes life after death, Satan (as Angra Mainyu), Heaven, and Hell. Most Shi'a Muslims accept Zoroastrians as People of the Book.
This definition is limited to those books that predate the Quran, they are seen as divine guidance from God to man that have been corrupted. This definition is not extended to followers of similar texts claiming divine guidance after the revelation of the Quran, as the Quran is seen as the final revelation and therefore any following are necessarily false.
Scholars have opinions as to whether or not Hinduism constitutes as a religion of The People of the Book. The Islamic conquest of India necessitated that this definition be revised, due to the majority of the inhabitants of India were followers of the Indian religions. Many of the Muslim clergy of India considered Hindus as people of the book, and from Muhhammad-bin-Kasim to Aurangzib, Muslim rules were willing to consider Hindus as people of the book. Many Muslims did not treat Hindus as pagans or idol-worshippers. However the concept of Adam, Eve and the various prophets of abrahamic religions does not exist in Hinduism.
Buddhism does not explicitly recognize a God, or the concept of prophethood. The Muslims however had at one point accorded them the status of "people of the Book" as well and Al-Biruni wrote of Buddha as the prophet "burxan". However, there is no official Buddhist view of God, and Buddhism does not specifically oppose monotheism. Brahman is recognised as the supreme Deva. However, it is explicitly stated in sutra that deva, including supreme Brahman is insufficient (or irrelevant or inferior) to attainment of enlightenment, as they are still trapped in cycle of rebirth. Moreover, Buddhism does not recognize God in the sense of Creator. Similar to hinduism, the concept of Adam, Eve and the various prophets of Abrahamic religions does not exist in the religion of Buddhism.
In the Qur'an
There are many statements in the Qur'an that promote tolerance towards People of The Book. For example:
And do not dispute with the followers of the Book except by what is best, except those of them who act unjustly, and say: We believe in that which has been revealed to us and revealed to you, and our God and your God is One, and to Him do we submit.[Qur'an29:46]
There are also many statements that promote an adversarial relationship. For example:
O you who believe! Do not take the Jews and the Christians for friends ; they are friends of each other; and whoever amongst you takes them for a ruler/patron, then surely he is one of them; surely God does not guide the unjust people.[Qur'an5:51]
In other places the Qur'an says:
Not all of them are alike; a party of the people of the Scripture stand for the right, they recite the Verses of God during the hours of the night, prostrating themselves in prayer. They believe in God and the Last Day; they enjoin Al-Ma'rûf and forbid Al-Munkar ; and they hasten in (all) good works; and they are among the righteous. And whatever good they do, nothing will be rejected of them; for God knows well those who are Al-Muttaqûn .(3:113-115)
And there are, certainly, among the people of the Scripture (Jews and Christians), those who believe in God and in that which has been revealed to you, and in that which has been revealed to them, humbling themselves before God. They do not sell the Verses of God for a little price, for them is a reward with their Lord. Surely, God is Swift in account. '(3:199)'
Verily! Those who believe and those who are Jews and Christians, and Sabians, whoever believes in God and the Last Day and do righteous good deeds shall have their reward with their Lord, on them shall be no fear, nor shall they grieve .[Qur'an2:62]
Say (O Muhammad ): "O people of the Scripture : Come to a word that is just between us and you, that we worship none but God, and that we associate no partners with Him, and that none of us shall take others as lords besides God.[Qur'an3:64]
Throughout Islamic history, Muslims have used these ayah (verses) to justify a variety of positions towards non-Muslims. In some places and times, Muslims showed a great deal of tolerance towards non-Muslims; in other places and times non-Muslims were treated as enemies and persecuted. Islamic law demands that Muslims treat Jews and Christians as dhimmis, protected citizens who have a number of rights.
One ayah in the Qur'an can even be interpreted to encourage a neutral position toward non-Muslims. This ayah says, "Those who follow the Jewish and the Sabi'een, Christians, Magians and Polytheists — Allah will judge them On the Day of Judgement:" (22:17). The acceptance of Zoroastrians as dhimmis is partly because of this ayah, as the Magians were Zurvanist Zoroastrians, and this verse, specifically mentions them alongside other People of the Book, and lists them ahead of polytheists.
Historically, a dhimmi was a person who is either guilty or protected (As the Arabic word means both.) under Islamic law by a pact contracted between non-Muslims and authorities from their Muslim government: this status was originally only made available to non-Muslims who were People of the Book (i.e. Jews and Christians), but was later extended to include Sikhs, Zoroastrians, Mandeans, Hindus and Buddhists. People of the Book living in non-Islamic nations were not considered dhimmis.
Non-Muslim People of the Book living in an Islamic nation under Sharia law were given a number of rights, such as the right to freely practice their faith in private, in return for state protection and exemption from military service. The social structure of the Ottoman Empire would serve as an example of how non-Muslims were treated. They also had some responsibilities, such as the payment of a special tax called jizyah ("tribute"), but were exempted from Zakat which Muslims are required to pay.
Because of the substantial Hindu tradition of monism, and the prominent Hindu theological perspective that there is a single Entity (Brahma) which sustains the world, Hindus eventually have been included as dhimmis.
The Yazidi, Druze and Azali faiths are small post-Islamic monotheistic faiths whose adherents mainly reside in Muslim-majority countries. Because they number very few and have seldom disturbed, countered or threatened Muslim authority, they are usually regarded as dhimmis.
The definition of "dhimmi" always excludes followers of the Bahá'í Faith. This is because the Bahá'í Faith, which grew out of Shi'a Islam, is a post-Islamic religion which does not accept the finality of Muhammad's revelation. Instead, Bahá'ís believe in the concept of progressive revelation, which states that God's will is progressively revealed through different teachers at different times, and that there will never be a final revelation.
The Ahmedis (usually referred to by Muslims as Qadianis) of Pakistan are also not regarded as dhimmis by the vast majority of Muslims. This is largely due to the fact that their prophet, Mirza Gulam Ahmed, came over 1,300 years after Muhammad, who is viewed as the "seal of the prophets" by Sunni, Shia, and Ibadi variants of Islam. They differ from other post-Islamic faiths in Muslim lands because Ahmedis first began as an Islamic reform movement, threatening the established orthodoxy present in South Asian Islam, and further was embraced by highly socially upward mobile westernizing Muslim intellectuals of the day. These factors, compounded with the presence of the colonial British authorities in India who had overthrown the Muslim Mughal Empire, led Muslims to view the presence of Ahmedis as a fifth column serving the British colonizers, and as a threat to "true" Islam. Pakistan to this day requires its citizens to swear an oath of allegiance to Islam, and declare Mirza Gulam Ahmed to be an apostate, should they elect to register as a Muslim for governmental services.
↑Hence for example such books as People of the Book: Thirty Scholars Reflect on Their Jewish Identity (Johns Hopkins University Press, 1997) and People of the Book: Canon, Meaning, and Authority (Harvard University Press, 1997).
↑ 5.05.1Desika Char, S. V. (1997). Hinduism and Islam in India: Caste, Religion, and Society from Antiquity to Early Modern Times. Markus Wiener Publishers. ISBN1558761519.
↑The Chach Nama English translation by Mirza Kalichbeg Fredunbeg. Delhi Reprint, 1979.
↑Annemarie Schimmel (2004), p.107, "The conqueror Muhammad Ibn Al Qasem gave both Hindus and Buddhists the same status as the Christians, Jews and Sabaeans in the Middle east". They were all "dhimmi" ('protected people')"
↑Thapar, R. 1993. Interpreting Early India. Delhi: Oxford University Press. p. 77