The graph is showing to you how many epochs you need to train your NN system in order to reach the minimum error required without over training . I this case about 20 epochs are enough. Now I have a question for you: what is the reason to put a graph like this one, and I guess that you have produced it, if you do not have any idea of what it means?
@ Alessandro Artusi firstly, thanks for ur respond.. yes you are right i get these graphs as result...sorry for inconvenience, it might be a stupid question.. but it has importance for me. as i am new.. i know that it is showing no. of epochs and min error..it is performance graph.. what i don't know is that why the line of best(BLack line) is moving on both axis?? .. mean on x-axis and y-axis ... i don't have much experience of reading graph... can u answer it...??