Foley sounds are everyday sound effects added to films to enhance audio quality. They are produced by Foley artists on a Foley stage where they synchronize sounds with footage cues. Common Foley sounds include footsteps, doors, and breaking glass. The technique is named after Jack Foley, who established modern Foley techniques. In horror films, Foley artists creatively use materials like leather and blades to reproduce sounds of killers' weapons and splattering blood, helping set an eerie atmosphere for viewers.