There are plants that live for one year only, or less, then die. Those are the annual plants. Tomatoes is one example of annual plants. There are plants that live for several years, those are called perennial plants. Trees are examples of perennial plants, for example fruit trees like apple and mango trees. There also exists a type of plants that grow for two years then die. They develop on two stages, during the first year they start growing then on the second year they give flowers and fruit. Plants belonging to this category are called biennial plants. Examples of biennial plants are onion and carrot.