How to graft a year old wild apple tree

We have seen, in a previous tutorial, how to give birth to an apple plant from apple seeds. Now, we will address the topic of graft. In fact, after a year of life, the plant will have to be grafted, in order to be able to bear flowers and fruit, because, as we have grown it, it will result in a wild apple tree. The graft can be carried out in the months of January or February, therefore, in winter. In order to graft it, we will have to take a twig, called marzètta, from another plant, from an adult apple tree. This marzètta must be of medium size. It will be taken in the middle part of the plant, i.e. in the middle, and will have to be of medium vigor. What will it mean? Which will be a not too big branch, therefore, quite young.