Socialization of a Dog means to introduce your Dog with people and with other dog breeds.
socialization is very important for your dog to behave nicely in outdoors.Socialization should
start at little age.Keeping your dog all the day in your yard would be a worst thing you can do with it.The more your dog meets with people and other dog breeds the more he/she will learn
to behave well not only with other people but also at home.Socialization helps reducing the aggression in your dog so in case of Pit Bulls it's a bit more important,but introducing your
adult Pit Bull to others can be a bit risky.In this case the owner should be more careful.
you should be careful in introducing your dog to others if you already know they are ill mannered.
In any way socialization of you dog plays an important role in developing your dog's skills.