Holi is a religious spring festival celebrated by Hindus as a festival of colours.It is mostly celebrated in India and Nepal. You can see it in many countries with large Indic diaspora populations. The festival is celebrated by people covering themselves and others in natural colors. The result of this celebration is an amazing multicolored scenery that is created in the streets.
Holi got its name as the "Festival of Colors" from Lord Krishna, a re-incarnation of Lord Vishnu, who liked to play pranks on the village girls by drenching them in water and colors.
It is celebrated in honor of the victory of good over evil, when demoness Holika got burned and destructed by the devotion to the Hindu god of preservation, Lord Vishnu.
Check some amazing photos of the celebration:
Source: Wikipedia and Goindia.about.com
Photos: Link,Link,Link,Link,Link,Link,Link