Energy flow within ecosystems describes how energy moves through different trophic levels, starting from producers to consumers and decomposers. This flow is essential for sustaining life, as it enables organisms to obtain the energy required for growth, reproduction, and maintenance. Through processes like photosynthesis, producers convert solar energy into chemical energy, which then transfers through food chains and webs. Understanding energy flow helps in assessing ecosystem health and determining how disturbances can impact the overall productivity and stability of the system.