Can anyone explaine me please, just start learn React, I’m confused in one thing in this code:

import { useState } from “react”;

import ReactDOM from “react-dom/client”;

function Car() {

const [car, setCar] = useState({

brand: "Ford",

model: "Mustang",

year: "1964",

color: "red"

});

const updateColor = () => {

setCar(previousState => {

  return { ...previousState, color: "blue" }

});

}

return (

<>

  <h1>My {car.brand}</h1>

  <p>

    It is a {car.color} {car.model} from {car.year}.

  </p>

  <button

    type="button"

    onClick={updateColor}

  >Blue</button>

</>

)

}

const root = ReactDOM.createRoot(document.getElementById(‘root’));

root.render();

previousState , If we only called setCar({color: “blue”}), this would remove the brand, model, and year from our state,
so previousState concatenating them, but how previousState accessed brand, model and year? ewhen they were attributed to him?

previousState is not a keyword no?