Riddle no 594(Solved by O.o Ashi .o.O)

[LoViNg IrFaN]

Main patla aur chota hun...kuch log mujh se sakht nafrat karte hain par kuch logon k lye main lazmi cheez hun... wo mere bger nhi reh sakte... wo mjhe din main kayi dafa use karte hain.... mujhe ek dafa roshan karte hain... par thori der bad main mar jata hun....main kafi logon ki mout ka sabab b banta hun.... kya hun main??