In The Outsiders by S.E. Hinton, both groups, the greasers and the socials, are more like packs than gangs. They are two groups, seperated by class, that hang out together.
Gangs are groups of people with the same intersts and values. Usually when you think of gangs, you think of people with criminal records, guns, fighting, colors, or symbols. Most of all, you think of violence. Neither the greasers or the socials fully fits this definition.
Packs are groups of people with the same interests or values, but there are differences. Packs or cliques usually start in school or very early in childhood. They are considered harmless and safe.
However, S.E. Hinton describes the Soc's as a being "a snarling, distrustful pack". The Socials would turn on one another and often fight with each other. The greasers were more like family. They were always there for one another and provided each other with support.
"We’re almost as close as brothers; when you grow up in a tight-knit neighborhood like ours, you get to know each other real well."