There are basically three types of samadhis in Vrindavana.
They are: full body, pushpa samadhi, and smriti (memory).
A full body samadhi contains the full body of a realized Vaishnava buried
in the earth. A pushpa samadhi is made by taking flowers worn by a departed
Vaishnava before his body is put into samadhi. These flowers are then
buried in a holy place. During the sixteenth century many Vaishnavas
were burned and their ashes were put into the ground to avoid desecration
by the Muslims. Samadhis made from the ashes of a Vaishnava also fall
in this category. A smriti (memory) samadhi preserves the memory of
a departed Vaishnava by memorializing some of his personal items. These
usually include an asana (sitting place), japa beads, clothes, sastras
(scriptures), shoes, a walking stick, etc. Things used by an elevated
Vaishnava are accepted as pure and worshipable.
In Vrindavana there is a danta (tooth) samadhi of Sri Gadadhara Pandit.
Another type of samadhi is a nama samadhi. Nama means "name". This type
of samadhi is established to remember and worship an exalted Vaishnava.
A nama samadhi consists of carving a Vaishnava's name on a block of
marble or granite and then putting that stone in a sacred place. There
are 64 nama samadhis near the Govindaji temple.
Normally a samadhis is placed near a temple or where a devotee did his
bhajana. It is said that Jiva Gosvami did bhajana in the exact same
place as where his samadhi is located. Lokanatha Gosvami, Bhugarbha
Gosvami and Prabodhananda Gosvami all did bhajana at the places where
their samadhis are located.