Why do my plant leaves have brown spots and how can I prevent or treat this issue?

Brown spots on plant leaves can be caused by various factors such as fungal infections, nutrient deficiencies, overwatering, or pests. To prevent or treat this issue, ensure your plant is receiving adequate sunlight, water, and nutrients. Avoid overwatering and make sure the plant has good air circulation. If the issue persists, consider using a fungicide or insecticide as needed.