Given the development based on sustainability and the pollution limits imposed to protect the environment, green finance (GF) has become a landmark in the finance ecosystem. The main topic addressed in this paper focuses on how the green approach to finance changes fundamental elements of the economy. Our study seeks to define the concept of the green finance ecosystem (GFE) by integrating historical evidence, research evolution, key components, international standards and policies, and theoretical foundations. This is achieved through a conceptual analysis supported by bibliometric and content analysis, complemented by a documentary and public policy review. Initially, we established the keywords used to identify the documents relevant to the state of the art. Subsequently, we analysed the identified documents using multiple types of analysis of the VosViewer software, and the most relevant ones were the subject of a content analysis. In total, 2317 papers published between 2007 and 2025 with the central theme of “financial ecosystem” and “sustainable development” or “green finance” form the basis of the bibliometric analysis (BA). The scientific mapping of key publications generated keywords networks, citations/countries, citations/authors, bibliographic coupling/countries, co-citation/sources and scientific performance that revealed dominant theoretical perspectives, emerging trends, leading research areas, and gaps in the literature. After BA, the content analysis was also extended to documents that debate fundamental theories related to green finance. Content analysis of theoretical elements helped us to trace an axis of historical development for the concept of green finance, highlighting the changes that have occurred over time. In addition, through a documentary and public policy analysis, we examined the key components of green finance, including green bonds, sustainable banking, and ESG investing. Furthermore, we explored fundamental theoretical frameworks such as sustainable finance theory, stakeholder theory, market failure and externalities theory, and green growth and ecological modernisation theory. Thus, the results of our work consist of structuring a comprehensive theoretical framework for the new concept of a green financial ecosystem, integrating the evolution, prospects and challenges faced by this sphere of finance. Our findings contribute to forming a coherent framework for GF, focusing on GFE and providing valuable insights for academics, policymakers and financial practitioners. In addition, defining this new concept of finance, GFE, helps in the future development of literature on the topic of interest, avoiding confusion with other finance branches.