Answer: The conflict between the greasers and the Socs is that they are rival gangs that are constantly fighting each other. As with most rivalries, there is always an old grievance to nurse. The greasers are the working-class kids and the Socs are the wealthy kids. The greasers dislike how adult society pardons the Socs for their innumerable transgressions, as well as how the Socs flaunt their wealth in the greasers' faces.
It's a rivalry between rich and poor.