Nikon D3300 - Manual (Page 138)

118 P, S, A, and M Modes
Exposure Compensation
Exposure compensation is used to alter exposure from the value
suggested by the camera, making pictures brighter or darker
(
0 345). It is most effective when used with M (Center-
weighted metering) or N (Spot metering) (0 114).
–1 EV No exposure
compensation
+1 EV