What is meaning of 'Projection' in Deep Learning?

Question

When i search for deep learning documents or paper,

sometimes i find 'Projection' on Deep learning.

but i don't know the definition of 'Projection'.

I think that the meaning of projection is change vector space to other vector space.

for example

# python code
X = np.zeros([200,100])
W = np.zeros([100,300])

XW = np.matmul(X,W) # XW shape is [200,300]

At this point, and i think X is projected onto XS. Am I correct?

Answer 1

Sounds like you might be referring to vector projection. I like lights, so if you imagine sitting directly under a light with your arm on a table before you... Keeping your elbow on the table, and raising your hand until your arm is at an angle into the air, the projected vector would then be the shadow of your arm/hand on the table!