Plant varieties refer to different types of plants within a species that have distinct characteristics. These differences can include variations in size, color, shape, and growth habits. For example, within the species of tomato, there are numerous varieties such as Roma, Cherry, and Beefsteak, each with unique flavors and uses in cooking. Plant varieties are important for agriculture and gardening because they can be selected for specific traits, such as disease resistance or climate adaptability. This selection helps farmers and gardeners grow plants that thrive in their local conditions, ensuring better yields and healthier crops.