There are many correct answers to this question, as humans use plants in many ways. One way is for food. Direct use is the food we consume. Examples of plants we consume include broccoli, cauliflower, and spinach. Related to foods, humans use plants to feed animals. In turn, the animals that are fed are used for purposes like for the human's own consumption.
Plants are also used for industrial purposes and in a number of products like oils, dyes, and shampoos. Thirdly, plants are used in medicine. Examples of medicines that include plants are aspirin, morphine, herbs, vincristine, and taxol.