description: Explore Ultralytics YOLO neural network modules, Proto to BottleneckCSP. Detailed explanation of each module with easy-to-follow code examples.
keywords: YOLO, Ultralytics, neural network, nn.modules.block, Proto, HGBlock, SPPF, C2, C3, RepC3, C3Ghost, Bottleneck, BottleneckCSP
Reference for ultralytics/nn/modules/block.py
!!! note
Full source code for this file is available at [https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/block.py](https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/block.py). Help us fix any issues you see by submitting a [Pull Request](https://docs.ultralytics.com/help/contributing/) 🛠️. Thank you 🙏!
::: ultralytics.nn.modules.block.DFL
::: ultralytics.nn.modules.block.Proto
::: ultralytics.nn.modules.block.HGStem
::: ultralytics.nn.modules.block.HGBlock
::: ultralytics.nn.modules.block.SPP
::: ultralytics.nn.modules.block.SPPF
::: ultralytics.nn.modules.block.C1
::: ultralytics.nn.modules.block.C2
::: ultralytics.nn.modules.block.C2f
::: ultralytics.nn.modules.block.C3
::: ultralytics.nn.modules.block.C3x
::: ultralytics.nn.modules.block.RepC3
::: ultralytics.nn.modules.block.C3TR
::: ultralytics.nn.modules.block.C3Ghost
::: ultralytics.nn.modules.block.GhostBottleneck
::: ultralytics.nn.modules.block.Bottleneck
::: ultralytics.nn.modules.block.BottleneckCSP