What do these three dots in React do?

Question

What does the ... do in this React (using JSX) code and what is it called?

Answer 1

const Profile =  {
          firstName: "kazi",
          lastName: "ahsan"
   }

const ProfileUpdate =  {
          firstName: "kazi",
          lastName: "ahsan"
 }


const newProfile = {...Profile, ...ProfileUpdate}

Hope this helps someone.