Structural violence is when a social structure or social institution hurts people by preventing them from getting their basic needs.
Unlike physical violence, there is no bloodshed and is not very obvious. However, people are still hurt and structural violence is tied to physical violence in a lot of ways.
A lot of social institutions are run by people who come from the advantaged classes. They want to make the social structures work for them so they make it hard for disadvantaged groups to live in society.
Structural violence is ... the main cause of behavioral violence on a socially and epidemiologically significant scale (from homicide and suicide to war and genocide). The question as to which of the two forms of violence—structural or behavioral—is more important, dangerous, or lethal is moot, for they are inextricably related to each other, as cause to effect.