Carbon stock is the quantitative measure of carbon held within a defined pool or reservoir at a specific point in time. This concept is a fundamental metric within environmental science, ecology, and climate change research, focusing on the total amount, spatial distribution, temporal dynamics, and drivers influencing carbon accumulation and depletion across various Earth system components, including terrestrial biomass (live and dead), soils, oceans, and the atmosphere. Key characteristics involve delineating specific carbon pools, employing diverse methodologies for measurement and estimation, and analyzing their relationship with carbon fluxes. Its significance lies in providing critical data for understanding global and regional carbon cycles, assessing ecosystem carbon sequestration capacity, evaluating climate change impacts, and informing mitigation and adaptation strategies.