Grafting onto is a horticultural technique where a part of one plant, called the scion, is attached to the root system of another plant, known as the rootstock. This method allows the scion to benefit from the rootstock's characteristics, such as disease resistance or improved growth. The process involves making precise cuts on both the scion and rootstock to ensure a successful union. Once joined, the plants grow together, allowing the scion to produce fruit or flowers while utilizing the rootstock's established root system for nutrients and water. This technique is commonly used in fruit tree cultivation, such as with apple or pear trees.