"paarsurrey,"
Namaste,
Both and neither, Hinduism is referring to Astika Dharma Darshans (Generally in this day and age Astika means those who accept the Veda as a valid means to acquire knowledge, Nastika would mean those who do not use Veda as a means of knowledge), it is part of a Larger set of Dharma Traditions where Astika and Nastika Darshans are both included. The Word Hindu may not be our original "Name", but if one is around for thousands of years one can assume many names and forms.
It is the concept of Dharmah that binds Hindus together, as no right minded Hindu would call oneself a Adharmic Hindu.
I don't completely agree with this, Hinduism is not "A", religion obviously, but neither is it a conglomerate of "religions", it is a a Blanket/umbrella term for many Darshan, Sampraday, Matta, Samaj, Sanghas, who all agree to some basic concepts such as Dharmah, Karma, PunaJanma ect religion is just a part of these multiple systems, even then the classical definition of "religion", if applied to the Hindu Dharmah may not completely describe the Dharmah.
Hope this helps