title: What is the point of GraphQL's ID Scalar?
body: <p><a href="https://graphql.org/learn/schema/#scalar-types" rel="noreferrer">https://graphql.org/learn/schema/#scalar-types</a></p>
  
  <p>I have read the description</p>
  
  <blockquote>
    <p><strong><code>ID</code></strong>: The ID scalar type represents a unique identifier, often used to refetch an object or as the key for a cache. The ID type is serialized in the same way as a String; however, defining it as an <strong><code>ID</code></strong> signifies that it is not intended to be human‐readable.</p>
  </blockquote>
  
  <p>But in practice, what actually changes if I use <code>ID</code> instead of <code>String</code> ? </p>