Let him know the rules of living with people.
The dog was originally a wild animal. Its ancestors were once free to run and chase in the vast land, and it still inherits various unique habits passed down from its ancestors.
These dogs are now entering the lives of people who are completely alien to them, and becoming part of a large family. If they are allowed to do as they please and are left unchecked, they will surely come into conflict in the future when they live together.
Thanks to the dog in the primitive era has been living in packs, absolute obedience to the command of the leader has become a kind of instinct that they continue the population from generation to generation.
Therefore, this instinct determines that after entering a new group (i.e. family), it is completely obedient to the leader of the group that it recognizes.
If we can utilize this nature of the dog, we can teach it to follow the various rules that should be followed when living with people, and this is the basis for training the dog.