**6. Routine challenges of deep learning**

According to Google trends graph more and more expert and professionals have attracted toward deep learning in last five year; the percentage of professionals increased from 12 to 100% [35, 36]. Deep learning is used everywhere, that is, bio-informatics, computer vision, IoT security, health-care, e-commerce, digital marketing, natural language processing, and many more [37, 38]. Because of the very hot research area, there must have some challenges which are enlisted below.
