Multimode fiber =large light carrying core, 62.5 microns or larger in diameter for short-distance transmissions with LED-based fiber optic equipment.
I have hand-drawn a picture of Multimode Fibre core as you can see Multimode fibers have a much larger core than single-mode shown below (50, 62.5 μm or even higher), allowing light transmission through different paths
Multimode fibre
Single-mode fiber =small light carrying core of 8 to 10 microns in diameter used for long-distance transmissions with laser diode-based fiber optic transmission equipment.
A Single-mode fiber core has a much smaller core, only about 9 microns so that the light travels in only one ray as shown below.
