Thank you for your answer.
I have a follow up question.
So I use the following code to define training and testing sets.
trainset = torchvision.datasets.CIFAR10(root='./data', train=True,  download=True, transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4, shuffle=True, num_workers=2)

testset = torchvision.datasets.CIFAR10(root='./data', train=False, download=True, transform=transform)
testloader = torch.utils.data.DataLoader(testset, batch_size=4, shuffle=False, num_workers=2)

My expectation was that by going to data folder, I see training and testing folders and images inside of them, but what I saw was just 8 files with these names: batches.meta, data_batch_1, data_batch_2, data_batch_3, data_batch_4,  data_batch_5, readme.html, and test_batch.
Can you please tell me what are they and how they are gonna be used? which one is for training and which one is for testing?
Thanks  a lot in advance