I am currently working on this assignment, and am a little confused. The assignment says this:

Remember that `train_set_x_orig`

is a numpy-array of shape (m_train, num_px, num_px, 3). For instance, you can access `m_train`

by writing `train_set_x_orig.shape[0]`

We’re supposed to define the following variables:

m_train =

# number of training examples

m_test =

# number of test examples

num_px =

What’s the difference between the number of training examples and the number of test examples? I thought those were the same thing? Is the number of training examples the number of times we have the network iterate gradient descent? And the number of test examples the number of images we input to calculate the gradient for each iteration of descent? I would then assume that num_px is the number of elements within each image. Just a little unclear on the details, and would appreciate any input. Thanks!