What does the 1 in torch.Size([64, 1, 28, 28]) mean when I check a tensor shape?
I'm following this tutorial on towardsdatascience.com because I wanted to try the MNIST dataset using Pytorch since I've already done it using keras.
So in Step 2, knowing the dataset better, they print the trainloader's shape and it returns torch.Size([64, 1, 28, 28]). I understand  that 64 is the number of images in that loader and that each one is a 28x28 image but what does the 1 mean exactly?

It simply defines an image of size 28x28 has 1 channel, which means it's a grayscale image. If it was a colored image then instead of 1 there would be 3 as the colored image has 3 channels such as RGB.
