A seed is a small, often hard structure that contains the embryo of a plant. It is produced by flowering plants, known as angiosperms, and is essential for reproduction. Seeds can vary in size, shape, and color, and they serve as a means for plants to spread and grow in new locations. When conditions are favorable, such as the right temperature and moisture, a seed can germinate. This process involves the seed absorbing water and swelling, eventually breaking open to allow the embryo to grow into a new plant. Seeds are vital for agriculture, providing food sources like grains and fruits.