Many people consider Hinduism to be different from Sanatan Dharma. They say that Europeans gave the name ‘Indu’, but Arabs used to pronounce ‘Hindu’, hence the name. Earlier its name was Sanatan Dharma. Then some say that no, earlier its name was Arya Dharma. Some say that no, earlier its name was Vedic religion. However, scholars think differently about this topic.
This path is eternal. All gods and human beings came to this world and progressed by following this path. O human beings, do not destroy your mother on the basis of your birth.'- (Rigveda-3-18-1)
Sanatan means that which is eternal, true forever. The things that have eternal importance are said to be Sanatan. As truth is eternal. God is the truth, the soul is the truth, salvation is the truth, and the only religion that guides the path of this truth is Sanatan Dharma. That truth which has been going on since time immemorial and which will never end, that is Sanatan or Eternal. That which has neither beginning nor end, that truth is called eternal. This is the truth of Sanatan Dharma.
Vedic or Hinduism is called Sanatan Dharma because it is the only religion, which tells the way to know God, Soul, and Moksha with Tattva and meditation. The concept of salvation is the gift of this religion. The path of salvation is the way of awakening and practice of Yama-Niyama including oneness, meditation, silence, and austerity, there is no other path to salvation. Self-knowledge and knowledge of God come from salvation. This is the truth of Sanatan Dharma.
When it comes to the basic elements of Sanatan Dharma, then those are mercy, forgiveness, non-violence, truth, chanting, charity, austerity, and more. All these have eternal importance. These principles were propounded in the Vedas before the rise of other major religions. There is no information about the starting date of Santan Dharma, hence the name, which indicates, it has no starting and ending point, it will go on and on for eternity.