What does parental advisory for music mean?

The parental advisory label on music albums warns that the content may be explicit and unsuitable for children. It was introduced in the United States in 1985 by the Recording Industry Association of America (RIAA) in response to concerns about the potential negative effects of music on young people. The label is voluntary, but most major record companies now use it on albums that contain lyrics that are sexually explicit, violent, or that make references to drugs or alcohol.