Quick answer
A typical G-string is minimal, but its narrow gusset and long center-back string create the problems the Y-String® was made to solve.
A G-string gives minimal lines, but the narrow gusset leads to lip slips and front slippage, while the long center-back string rubs up and down and causes wedgies, rubbing, and irritation. The Y-String® keeps the minimal look but adds a wider gusset, better front coverage, our signature string design, and soft cotton comfort.
The difference
The Y-String® keeps the minimal look and changes the parts that make G-strings uncomfortable.
Traditional G-strings are built to be tiny, but that usually means less front coverage and more friction in the back. The narrow gusset leads to lip slips, and the long center-back string causes wedgies, rubbing, and irritation.
The Y-String® is designed differently. The wider gusset gives better front coverage, while the signature string design is shaped more like an upside-down Y to provide coverage where you need it and prevent wedgies without giving up minimal lines.