be given a lotta on label samples now labeling is a time-consuming process and potentially very expensive and actually pretty hard in certain domains like medicine right so or detecting rare events and sub driving for them for that matter so if you have a lot of unlabeled data and your training data set can be reprime tries now is having some lis pairs of label data points image command label and also a lot of other data points where you just have the image and your goal is take this extra data extra data points where you don't have labels