For new researchers in the field of deep learning, this review can help them to obtain many details about the advantages, disadvantages, applications, and working mechanisms of a number of deep learning  ...  By presenting many challenges of deep learning in one section, we hope to increase awareness of these challenges, and how they can be dealt with.  ...  Acknowledgments: The authors would like to thank the Arab Open University for supporting this research paper. Conflicts of Interest: The authors declare no conflict of interest.  ...