Seamstress and sewer are related, but they are not exactly the same.
Seamstress
A seamstress traditionally refers to someone, usually a woman, who sews garments and focuses on custom work, alterations, or dressmaking. This term is commonly associated with tailoring shops, bridal boutiques, and home-based businesses, emphasizing skill in garment construction, fitting, and finishing.
Sewer
A sewer is a gender-neutral term for someone who sews in a professional or industrial context, often in garment factories, upholstery production, or other manufacturing settings. This role typically involves following patterns, operating sewing machines, and producing items at scale, rather than creating custom or individually fitted clothing.