Regarding training and validation accuracy

I have trained the CNN model for dataset of 220 images and attained the results as shown below:

Is this network overfit or not?? Can I consider these results genuine for further study? What is difference between mini-batch loss and validation loss? what is perfect size of mini-batch for these number of images? Can CNN be applied to small image datatsets?

[KSSV]

To find out net is overfit or not, test it with the known data. Rest of the definitions are given at the doc.