The word 'Hindu' and 'Arya' is mentioned in the Avesta, the religion book of the Zoroastrians of Iranians. Other historians, on the other hand, believe that the Hindu word originated from Indu during the time of the Chinese traveler Huensang. The word Indu that comes from the river Indus is also synonymous with the moon. The basis of Indian astrological calculations is the moonrise itself. Hence, the people of China began to call the Indians 'Intu' or 'Hindus'.
Some scholars believe that the word Hindu has come from the Himalayas. The Hindu Kush Mountain is an example. The word Hindu is not an indirect word, otherwise, the Sindhu river is also not called a Hindu. There are many theories around the origination of the term ‘Hindu’, but the people who follow the religion say that they are following ‘Sanatana Dharma’. The meaning of Sanatana Dharma means a religion that has no starting and ending point.
Aryattva: the people of Aryan society call it Aryan religion, whereas Arya is considered to be the only superior meaning, not the name of any caste or religion. That is, one who is superior in mind, word, and deed is Arya. The Four Noble Truths of Buddhism mean Four Noble Truths. Buddha says that knowing the above Noble and eternal truth, following the Eightfold Path is, 'dhammo sanantano', that is, Sanatan Dharma.
Thus, Arya Dharma means the religion of the elevated society. Ancient India was also called Aryavarta, which meant the land of the residence of the superior.