If you grow plants, often you can propagate the plant with cuttings. Tomatoes are a great example.
In the photo I have indicated in red where "suckers" exist. These stems will not produce fruit on this plant but will take energy and nutrition that could go to produce more and larger fruits. So they should be pruned (cut) from the plant.
If you want more of that plants of that kind of tomato, you can take that cutting and either place it in water or in soil and it will root. Now you have anoth