JSON-LD
JSON-LD (JavaScript Object Notation for Linked Data) is the format Google recommends for adding structured data to a page. It is a small block of code in your page's HTML that labels your product's facts for machines.
How it works
JSON-LD uses the schema.org vocabulary to state, in a machine-readable way, that a value is the price, another is the brand, and the item is in stock. It sits in the HTML your server sends. Since AI crawlers mostly do not run JavaScript, the JSON-LD needs to be in that initial response, not added later in the browser.
A commerce example
Your page shows the price in a styled graphic a person reads instantly. In JSON-LD, that same price is stated as data, so an agent reading the raw HTML can quote it with confidence rather than guessing.
What this means for your store
On Shopify and WooCommerce your platform or SEO plugin usually outputs JSON-LD for products. Confirm it covers brand and identifiers, and test a page with Google's Rich Results Test.