Hand-pollination is a process where humans help plants make babies. You know how mommy and daddy make babies? Well, plants do that too, but they need a little help sometimes. When plants make babies, they grow seeds that turn into new baby plants. But in order for the baby plants to grow, the seeds need to be fertilized.
Fertilization is like magic dust that makes the seeds grow. Most plants get fertilized when bees fly around and spread the magic dust from flower to flower. But sometimes there aren't enough bees, or the plant is in a place where there are no bees, so humans have to do the job.
To hand-pollinate a plant, you need to take a little brush or a Q-tip and collect some of the magic dust from one flower. Then, you have to carefully brush the magic dust onto a different flower. That way, the new flower can make babies and grow new plants.
Sometimes, people will also hand-pollinate plants to create new kinds of plants. They might take some magic dust from one kind of plant and put it onto a different kind of plant. This can create a new kind of plant with different colors or shapes.
In summary, hand-pollination is when people help plants make babies by taking magic dust from one flower and putting it onto another flower so that it can grow into a new plant.