Folding the paper in thirds creates six panels with the right panel tucked inside the panels created by the first fold
This works well for brochures that have an average amount of information and graphics/photos to present in a cost-effective format. It gives you a front “cover” panel, a large inside of 3 panels that can divide information per panel or spread it out across the entire opened brochure, and a back panel for contact information.
See also: single fold, accordion fold, gate fold, zig-zag fold, barrel fold, french fold, map fold