AI is advancing by leaps and bounds in learning algorithm development, but AI has many challenges when put to practice. One of the major challenges faced by AI is the serious lack of data, which has led to the inability of many good algorithm models to be effectively applied. Another major challenge is the need to protect user privacy and security in many AI applications. In this talk, Prof. Yang will present federated learning as a solution designed to connect data silos while protecting user privacy and provide security. Prof. Yang will illustrate some theoretical advances and practical applications.