Seam Allowance

The distance between the raw edge and where the seam is sewn. Another way to define it is the difference between the edge of the fabric and the finished size of the unit or block. In quiltmaking, the seam allowance is usually 1/4 of an inch (7.5mm).  In garment sewing, the seam allowance is traditionally 5/8″ (15 mm).

https://scissortailquilting.com/glossary/seam-allowance/