One straightforward definition of biotechnology I really like is that it is technology that utilizes biological systems, living organisms or parts of this to develop or create different products. It’s the definition I use because it is uncomplicated and sticks to the basics. Unfortunately, since people already realize that the term "biotechnology" is made up of bio + technology, this definition does not answer the question people are really asking. They invariably want to know two things: What is biotechnology used for? How does it work? Let's keep it simple and start with bread.
What? We use biotechnology when we make leavened bread.
How? We use biotechnology by taking advantage of the natural activity of living organisms or parts of biological systems to reach our goal. Think about it: Yeast is a living organism. You can see that for yourself if the water you add at the start is too hot. The yeast will die because it does best under conditions that provide the ideal environment for its growth. Yeast doesn’t set out to turn flour into bread. It sets out to thrive and feed itself. During the process of fermentation, the yeast feeds on the sugars in the flour and expels carbon dioxide. Bubbles of carbon dioxide become caught by the gluten in the dough and the bread rises. In this instance, bio = Yeast + technology = Kneading/Resting/Baking. Biotechnology!