Overpopulation occurs when the number of people in a specific area exceeds the resources available to support them. This can lead to issues such as inadequate food, water, and housing, as well as increased pollution and environmental degradation. Factors contributing to overpopulation include high birth rates, decreased mortality rates due to medical advancements, and migration. Areas most affected often struggle with economic challenges and social unrest, making it difficult to provide essential services like education and healthcare.