What is the "spatial information" in convolutional neural network
Spatial Information refers to information having location-based relation with other information.

For example,
00100
01100
00100
00100

This looks like the number "1".

If this was represented in a single line,
001100011100001100001100

It wouldn't be recognizable.

Earlier layers of CNN are convolutional layers, which take into account the image as a 2D (spatial) information. Whereas, the deeper layers flatten that (convoluted) information.