This article provides an in-depth review of renewable energy communities (RECs), exploring their concepts, scope, benefits, and key activities. It discusses the progress, challenges, and recommendations for enhancing the growth of RECs. The article emphasizes the importance of citizen involvement and offers insights into various aspects of community energy for sustainable energy transition. It also provides practical insights and valuable information for policymakers, researchers, industry professionals, and community members who are keen on promoting sustainable, community-driven energy systems. The concept of energy communities is central to the European Union's energy strategy, aiming to transition to a decentralized and adaptable energy system. RECs are defined as community-based initiatives that utilize renewable energy sources (RESs) and involve citizens in energy generation, consumption, and management. The European Union's Renewable Energy Directive II (RED II) sets a legally binding goal of 32% renewable energy in the EU's gross final energy consumption by 2030, promoting the development of RECs. The article discusses the different types of energy communities, including homogeneous energy communities (HECs), mixed energy communities (MECs), and self-sufficient energy communities (SECs). It highlights the benefits of RECs, such as local production of renewable energy, socioeconomic and environmental benefits, sustainable energy transition, citizen governance, policy governance, and innovation. The main activities of RECs include energy generation, energy storage systems, energy sharing, energy efficiency measures, data monitoring and analytics, and virtual power plants (VPPs). The article also discusses the challenges faced by RECs, such as policy and regulatory barriers, technical challenges, and the need for increased awareness and education. It provides recommendations for enhancing the growth of RECs, including the development of supportive policies, investment in renewable energy technologies, and the promotion of community engagement and participation. The article concludes that RECs play a vital role in achieving a sustainable and resilient energy future, emphasizing the importance of citizen involvement and community-driven energy systems.This article provides an in-depth review of renewable energy communities (RECs), exploring their concepts, scope, benefits, and key activities. It discusses the progress, challenges, and recommendations for enhancing the growth of RECs. The article emphasizes the importance of citizen involvement and offers insights into various aspects of community energy for sustainable energy transition. It also provides practical insights and valuable information for policymakers, researchers, industry professionals, and community members who are keen on promoting sustainable, community-driven energy systems. The concept of energy communities is central to the European Union's energy strategy, aiming to transition to a decentralized and adaptable energy system. RECs are defined as community-based initiatives that utilize renewable energy sources (RESs) and involve citizens in energy generation, consumption, and management. The European Union's Renewable Energy Directive II (RED II) sets a legally binding goal of 32% renewable energy in the EU's gross final energy consumption by 2030, promoting the development of RECs. The article discusses the different types of energy communities, including homogeneous energy communities (HECs), mixed energy communities (MECs), and self-sufficient energy communities (SECs). It highlights the benefits of RECs, such as local production of renewable energy, socioeconomic and environmental benefits, sustainable energy transition, citizen governance, policy governance, and innovation. The main activities of RECs include energy generation, energy storage systems, energy sharing, energy efficiency measures, data monitoring and analytics, and virtual power plants (VPPs). The article also discusses the challenges faced by RECs, such as policy and regulatory barriers, technical challenges, and the need for increased awareness and education. It provides recommendations for enhancing the growth of RECs, including the development of supportive policies, investment in renewable energy technologies, and the promotion of community engagement and participation. The article concludes that RECs play a vital role in achieving a sustainable and resilient energy future, emphasizing the importance of citizen involvement and community-driven energy systems.