Nikon D5300 - Manual (Page 103)

83 P, S, A, and M Modes
A
Shutter Speed and Aperture
Shutter speed and aperture are shown in the viewfinder and information display.
Shutter speed
Aperture
Fast shutter speeds ( 1 /
1600
s in this example)
freeze motion.
Slow shutter speeds (here 1 s) blur motion.
Large apertures (such as f/5.6; remember, the
lower the f-number, the larger the aperture)
blur details in front of and behind the main
subject.
Small apertures (f/22 in this case) bring both
background and foreground into focus.