A CNN often used to split images into pixel-level parts.
U-Net is like a fussy kid with a coloring book. It colors only the cat, not the couch.
It is common in medical scan work. Diffusion models also use it to clean noise and rebuild images step by step.
CNN
U-Net is a classic variant of a CNN.
Computer Vision
U-Net mainly helps with image segmentation in Computer Vision.
Diffusion
Many Diffusion models use U-Net as the main denoising network.
ResNet
U-Net and ResNet are both classic vision designs, but they focus on different jobs.