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A 2D shape is flat. It has length and width but no height - hence no volume.
A 3D volume has length, width  and  height - hence also a volume.

as the name suggests 2d means 2 dimensional or it is made on 2 axes : x and y

while, 3d means 3 dimensional object or it is made on 3 axes : x,y & z...

4. Map is a visual representation of an area, whether real or imaginary.
Picture is a representation of anything upon canvas, paper, or other surface, by drawing, painting, printing, etc.

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