PUPPY SOCIALIZATION 
Socialization is the first step in raising a well-behaved dog. During the first weeks of their lives, puppies go through a critical period of development. When a puppy is exposed to new people, places, and situations in a positive way during this period, there's a good chance he'll be calm and accepting when he experiences them again later in life.
What Exactly Is Socialization?
Socialization is just what it sounds like - socializing. Your puppy should meet and interact with as many types of people, animals, and environments as possible. By the time he reaches about 4 months old, your puppy should learn to accept being petted by strangers, meeting other dogs, being handled by a veterinarian or groomer, and meeting a wide variety of people.
Why Is Socialization So Important?
Socializing your puppy helps him to become a happy, healthy, and well-behaved member of your family. Properly socialized puppies are less likely to develop behavioral problems as they grow into adults. Dogs that don't get early socialization may react with fear or aggression when they are exposed to new things. It is much easier to teach your puppy to accept new things now than it is to retrain him after bad habits develop.