How do different algorithms work?

Hello，I want to ask for a help：
In the "main_fedml_image_segmentation. py" file of the fedcv module, "SegmentationTrainer. py" and "SegmentationAggregator. py" under the "image_segmentation/trainer" module are imported during training.
Suppose I modify different algorithms in "fedml_config. yaml", such as FedAvg, FedOpt, FedProx, but still use the same SegmentationTrainer and SegmentationAggregator, without any difference? How should different algorithms be implemented?
In fedcv/segmentation， how do the algorithms in fedml/simulation/mpi work? They are all the same?