Happy Deepavali

The name "Diwali" is a contraction of "Deepavali" (Sanskrit: 
 दीपावली Dīpāvalī), which translates into "row of lamps".
Diwali involves the lighting of small clay lamps (dīpa in  
Sanskrit: दीप) filled with oil to signify the triumph of good over evil.  
These lamps are kept on during the night and one's house is cleaned, 
both done in order to make the goddess Lakshmi feel welcome. 

Firecrackers are burst in order to drive away evil spirits.
Diwali commemorates the return of Lord Rama, along with Sita and 
Lakshmana, from his 14-year-long exile and vanquishing the 
demon-king  Ravana. In joyous celebration of the return of their 
king, the people of Ayodhya, the Capital of Rama, illuminated the 
kingdom with earthen  diyas and by bursting firecrackers.