Planting density refers to the number of plants grown in a specific area, usually measured in plants per square meter. It plays a crucial role in agriculture and gardening, as it affects plant growth, yield, and resource competition. Higher densities can lead to increased competition for light, water, and nutrients, while lower densities may allow for better air circulation and access to resources. Choosing the right planting density depends on various factors, including the type of crop, soil quality, and climate conditions. For instance, corn typically requires a higher planting density compared to tomatoes, which may thrive better with more space between plants.