In the growing world of artificial intelligence, federated learning is a distributed learning framework enhanced to preserve the privacy of individuals' data. Federated learning lays the groundwork for collaborative research in areas where the data is sensitive. Federated learning has several implications for real-world problems. In times of crisis, when real-time decision-making is critical, federated learning allows multiple entities to work collectively without sharing sensitive data. This distributed approach enables us to leverage information from multiple sources and gain more diverse insights. This paper is a systematic review of the literature on privacy-preserving machine learning in the last few years based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Specifically, we have presented an extensive review of supervised/unsupervised machine learning algorithms, ensemble methods, meta-heuristic approaches, blockchain technology, and reinforcement learning used in the framework of federated learning, in addition to an overview of federated learning applications. This paper reviews the literature on the components of federated learning and its applications in the last few years. The main purpose of this work is to provide researchers and practitioners with a comprehensive overview of federated learning from the machine learning point of view. A discussion of some open problems and future research directions in federated learning is also provided.

分布式学习框架-联邦学习增强了个人数据隐私保护，允许协作研究且无需共享敏感数据；通过多源信息合作，提供更多种类的洞察力。本文是对隐私保护机器学习的系统性文献综述，通过PRISMA指南对近年来得出的有关联邦学习的监督/非监督机器学习算法、集成方法、元启发式方法、区块链技术和强化学习，以及联邦学习应用进行了广泛回顾。旨在为研究人员和实践者提供从机器学习角度对联邦学习的全面概述，并提供了一些开放问题和未来研究方向的讨论。

探索联邦学习的机器学习模型：方法、性能和限制的综述