Difference Module

[bo123bo321]

Hello, can you introduce the principle of this module

def conv_diff(in_channels, out_channels):
return nn.Sequential(
nn.Conv2d(in_channels, out_channels, kernel_size=3, padding=1),
nn.ReLU(),
nn.BatchNorm2d(out_channels),
nn.Conv2d(out_channels, out_channels, kernel_size=3, padding=1),
nn.ReLU()
)

[bo123bo321]

Why does this module have A similar function as abs (A-B)