All flowering plants produce seed. A seed usually has a hard coating to stop it from drying out. Inside the seed is a store of food which will feed the tiny new plant as it starts to develop. This is important as at first the new shoot does not have leaves with which to produce food for itself. The tiny embryo plant is also inside the seed shell waiting for just the right time to start growing.
Seeds provide nourishing food for people and animals too. Try making a list of all the different types of foods that we eat which are produced from seeds.