This is taken from a book called HINDUISM, HINDU DHARMA AND SANAATHANA DHARMA WRITTEN BY DR.N.GOPALAKRISHNAN,PHD, D.Litt.
This book beautifully brings to us that Hinduism is not a religion, as it is understood. Those who consider and live in the part of the country, which extends from Indus valley or Sindu River up to Indian Ocean, are known as Hindus (which can be rightly Indian or Bharatham as it is called). Unlike other religions it is not formed by single individuals but by thousands of Rishies, during a course of several thousands of years could formulate a perfect style or way of thinking and practicing various aspects and concepts of life. Those are codified as the customs and rituals known as
acharas. These acharas combined together to form dharma or way of life. Thus we can conclude that Hinduism is the way of life. According to Bagawat geetha our dharma is know as sanathana means one which indestructible and is ever lasting. He defines the following terms DHARMA: is the one, which is guiding, protecting and supporting principles of ones life. ACHARA’S: Every one practiced his or her dharma through acharas. These acharas are practiced for psychological, physiological, stronger family related benefits, social bondage and finally national integration based benefits. For example Achara performed by mother is known as maathru
dharama; by father known as pitru dharma; by son is known as putra dharma; by husband is known as bhartru dharma; and wife is know as patnee dharma and other citizens –poura dharma; for teachers- acharya dharma; for the king Raja dharma SANAATHANA DHARMA: Now the book brings home what is sandahana dharama. Sanadhana dharma is infact combination of all the dharma –maatrudharma (mother), pitru dharma (father), putra dharma (son), putree dharma (daughter), bhartru dharma (husband), patnee dharma (wife), poura dharma (citizens), acharya dharma (teachers) and raja dharma (king). It brings us those those who live in the regions extending from Sindu River to Indian Ocean is rightly called Hindus without considering the religious, caste sex or any social set up within that area. So Christians living in the same part (region between sindhu river and Indian ocean) are Hindu Christian and Muslims living in the same area are known as Hindu Muslims, JUST LIKE WE SAY AMERICAN CHRISTIAN AND PAKISTANI MUSLIMS.
Note:Most of the words are sanskrit words and english meaning is explained and some given in bracket.