Friendship and Socialization are two different things though they may sound as the same. Friendship is more personal and informal thing where one seeks care, love, affection and a strong sense of connection. Whereas socialization is not so personal but more to be in a group and is formal.
Normally, in companies when people are hired, they are put into training to learn about the organization, its people, system and processes. All these things start very formally as socialization but with time it may forge friendship with few. Even companies prefer team members to know each other before they start working together. They want a sense of bonding among its workforce to have a productive and better work environment.