Char Dham - means four sacred places in India as per Hindu
belief. They are PURI, DWARKA, BADRINATH and RAMESHWARAM -
collectively known as the Chardham of India are the most sacred of
all pilgrimages. It is believed that undertaking a journey to these
holy shrines located in the four corners of India washes away one's
sins and relieves one from the cycle of birth and death. However,
some people called these places as Char Dham - Yamunotri, Gangotri,
Kedarnath & Badrinathji (in Uttaranchal) - which although
sacred, are not actually char dham. Any Dham is a revered place,
but "Char Dham" actually refers to - Puri, Dwarka, Badrinath &
Rameshwaram - where live four Shankaracharyas. Please refer this
link -
http://www.oktatabyebye.com/travel-ideas/pilgrimage-india/chardham-yatra-India.aspx