With the spread of DX and remote work, the use of the cloud by companies is increasing, and the news of information leakage from the cloud is also increasing regardless of IaaS/PaaS/SaaS. "Cloud security" is important to protect assets on the cloud from information leaks and other threats. However, the scope of its application is wide and complicated, so it seems that the current situation is that it is difficult to grasp the whole picture of cloud security. In this session, we will introduce the risks in using and managing the cloud, and explain in an easy-to-understand manner the overall picture of cloud security and what countermeasures are available.