The URL slug for a product.
The handle is derived from the product title (`Blue Cotton Shirt` → `blue-cotton-shirt`) but is editable. Changing a handle changes the product's public URL, which breaks any external link, ad, email or backlink that points to the old address. Always set up a 301 URL redirect in Online Store → Navigation before publishing a handle change, and prefer editing handles once, at launch, rather than during peak season.
