Building Energy Management Systems (BEMS) are essential for improving energy efficiency and sustainability in buildings. This review article discusses the components, benefits, challenges, and future trends of BEMS. BEMS are centralized systems that monitor and control building services such as heating, ventilation, air conditioning, lighting, and other systems to enhance energy efficiency and occupant comfort. Key components of BEMS include sensors, controllers, communication networks, and user interfaces, which work together to collect data, analyze energy consumption patterns, and optimize system operation. BEMS help reduce energy consumption and costs by monitoring and controlling building systems based on occupancy schedules and environmental conditions. They also improve occupant comfort and productivity by maintaining optimal indoor environmental conditions. Despite their benefits, BEMS face challenges such as high upfront costs, complexity of installation, and integration issues with existing building systems. However, advancements in technology, such as the Internet of Things (IoT), cloud computing, artificial intelligence (AI), and machine learning, are addressing these challenges and making BEMS more accessible and cost-effective. The future of BEMS is promising, with continued advancements in technology driving their adoption and integration into smart building systems. The integration of AI and machine learning into BEMS is expected to further improve their energy-saving capabilities and enhance building performance. Case studies show that BEMS can lead to significant energy savings, cost reductions, and operational improvements in various buildings. The Empire State Building, The Crystal, Microsoft's campus, and the University of California, Berkeley, have all implemented BEMS with positive results. Future trends in BEMS include integration with smart building systems, enhanced energy-saving capabilities through AI and machine learning, and the role of BEMS in achieving sustainability goals. BEMS are crucial for achieving energy efficiency and sustainability goals in buildings by monitoring and controlling energy usage, optimizing building systems, and providing real-time data insights. By leveraging the components, benefits, and advancements of BEMS, organizations can achieve significant energy savings, cost reductions, and environmental benefits.Building Energy Management Systems (BEMS) are essential for improving energy efficiency and sustainability in buildings. This review article discusses the components, benefits, challenges, and future trends of BEMS. BEMS are centralized systems that monitor and control building services such as heating, ventilation, air conditioning, lighting, and other systems to enhance energy efficiency and occupant comfort. Key components of BEMS include sensors, controllers, communication networks, and user interfaces, which work together to collect data, analyze energy consumption patterns, and optimize system operation. BEMS help reduce energy consumption and costs by monitoring and controlling building systems based on occupancy schedules and environmental conditions. They also improve occupant comfort and productivity by maintaining optimal indoor environmental conditions. Despite their benefits, BEMS face challenges such as high upfront costs, complexity of installation, and integration issues with existing building systems. However, advancements in technology, such as the Internet of Things (IoT), cloud computing, artificial intelligence (AI), and machine learning, are addressing these challenges and making BEMS more accessible and cost-effective. The future of BEMS is promising, with continued advancements in technology driving their adoption and integration into smart building systems. The integration of AI and machine learning into BEMS is expected to further improve their energy-saving capabilities and enhance building performance. Case studies show that BEMS can lead to significant energy savings, cost reductions, and operational improvements in various buildings. The Empire State Building, The Crystal, Microsoft's campus, and the University of California, Berkeley, have all implemented BEMS with positive results. Future trends in BEMS include integration with smart building systems, enhanced energy-saving capabilities through AI and machine learning, and the role of BEMS in achieving sustainability goals. BEMS are crucial for achieving energy efficiency and sustainability goals in buildings by monitoring and controlling energy usage, optimizing building systems, and providing real-time data insights. By leveraging the components, benefits, and advancements of BEMS, organizations can achieve significant energy savings, cost reductions, and environmental benefits.