Epoch - a term to indicate progress through the process of training a neural net. An epoch is an iteration through the complete training data (i.e., every single training file has been processed through the model).

Step - like epoch, this is a term to indicate progress through the process of training a neural net. A step is generally an iteration through a defined subset of the training data. The training data is generally divided into batches because the memory required to process the complete training dataset is larger than available to the computer.