Key Structural Difference
A corner sofa has a dedicated corner unit — typically 100 cm × 100 cm — that forms the pivot point of the design. This corner unit contains the hinge of the seating system and is integral to the frame. Remove it and neither side functions properly. An L-shaped modular sofa achieves the same visual shape by placing a separate chaise or section at a right angle to the main sofa. The connection is mechanical (bolts or brackets), not structural. The modular version is more flexible but the join point is a potential weak spot if the bracket is not robust.