The Ekadashi that falls on the Krishna paksha of Ashada month of the Hindu calendar,i.e the elevnth day of the waning phase of the moon of the Ashada month of Hindu calendar is known as Kamika Ekadashi.
The meaning of Kamika is a desire to be fulfilled.
People perform the Ekadashi Vrat as it is observed on all the other Ekadashis. It is believed that by observing the vrat on this day one would be blessed and his desires will fulfilled.It is considered that if one worships lord Vishnu with Tulsi leaves (Basil leaves), it is equivalent of getting the Punya of bathing in all the sacred rivers and also doing 100 yagnas.