.json()

.json is an asynchronous method that parses a stringified json response body to a Javascript object.

Because json() method is an asynchronous method, if you don't await the response, it returns an unresolved Promise object.

fetch('https://example.org/products.json')
  .then(response => response.json()) // not async code
  // callback is executed after fulfillment
  // returns Promise wrapped data to next .then chain
  .then(data => {
    // another fulfilled Promise
    console.log(data)
  })

Alternative:

const response = await fetch('https://example.org/products.json');

const data = await response.json(); // is async