Conflict can occur on an interpersonal level or on a large social level. Conflict, broadly defined, is a power struggle between two entities.
Violence occurs when one person or group of people physically harms or threatens another person or individual. Threatening someone with harm, while not physically overt, is still an act of violence.
Conflict and violence cause pain, suffering and the dissolution of unity in groups of families, friends, co-workers and nations.
Conflict resolution is a growing field, as is the study of conflict and violence itself. Conflict mediators are called upon in interpersonal situations, such as family conflicts, as well as global political crises, such as wars.
Not all conflict leads to violence. And not all violence stems from an identifiable, reasonable conflict. Things like mental illnesses and violence for personal gain complicate the relationship between these two concepts.