What is the main difference between primary and secondary succession?

Primary succession is the process in which plants and animals first colonize a barren habitat. Secondary succession differs from primary succession in that it begins after a major disturbance—such as a devastating flood, wildfire, landslide, lava flow, or human activity (farming, road or building construction, or the like)—wipes away part of a landscape.

cuz some people don't have enough food. that's why we need more ppl to donate food to the hungry.