Building Energy Management Systems (BEMS) are advanced technology platforms designed to monitor, control, and optimize energy usage in commercial, industrial, and residential buildings. This comprehensive review covers the components, benefits, challenges, and future trends of BEMS. Key components include sensors, controllers, communication networks, and user interfaces, which work together to collect and analyze data, optimize system operation, and improve energy efficiency. BEMS offer significant benefits such as reduced energy consumption, lower costs, improved occupant comfort, and enhanced productivity. However, they also face challenges like high upfront costs, installation complexity, integration issues, and data security concerns. Technological advancements, including IoT integration, cloud computing, AI, and machine learning, are enhancing BEMS capabilities, making them more efficient and intelligent. Case studies from various buildings demonstrate the effectiveness of BEMS in achieving energy savings and operational improvements. Future trends include integration with smart building systems, enhanced energy-saving capabilities through AI and ML, and the role of BEMS in achieving sustainability goals. Overall, BEMS are crucial for improving energy efficiency and sustainability in buildings, and their continued development and adoption are essential for a more sustainable built environment.Building Energy Management Systems (BEMS) are advanced technology platforms designed to monitor, control, and optimize energy usage in commercial, industrial, and residential buildings. This comprehensive review covers the components, benefits, challenges, and future trends of BEMS. Key components include sensors, controllers, communication networks, and user interfaces, which work together to collect and analyze data, optimize system operation, and improve energy efficiency. BEMS offer significant benefits such as reduced energy consumption, lower costs, improved occupant comfort, and enhanced productivity. However, they also face challenges like high upfront costs, installation complexity, integration issues, and data security concerns. Technological advancements, including IoT integration, cloud computing, AI, and machine learning, are enhancing BEMS capabilities, making them more efficient and intelligent. Case studies from various buildings demonstrate the effectiveness of BEMS in achieving energy savings and operational improvements. Future trends include integration with smart building systems, enhanced energy-saving capabilities through AI and ML, and the role of BEMS in achieving sustainability goals. Overall, BEMS are crucial for improving energy efficiency and sustainability in buildings, and their continued development and adoption are essential for a more sustainable built environment.