difference between gridview and gridview builder in flutter code example

Example 1: flutter grid view

GridView.count(
  primary: false,
  padding: const EdgeInsets.all(20),
  crossAxisSpacing: 10,
  mainAxisSpacing: 10,
  crossAxisCount: 2,
  children: <Widget>[
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text("He'd have you all unravel at the"),
      color: Colors.teal[100],
    ),
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text('Heed not the rabble'),
      color: Colors.teal[200],
    ),
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text('Sound of screams but the'),
      color: Colors.teal[300],
    ),
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text('Who scream'),
      color: Colors.teal[400],
    ),
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text('Revolution is coming...'),
      color: Colors.teal[500],
    ),
    Container(
      padding: const EdgeInsets.all(8),
      child: const Text('Revolution, they...'),
      color: Colors.teal[600],
    ),
  ],
)

Example 2: gridview flutter

GridView.count(
  // Create a grid with 2 columns. If you change the scrollDirection to
  // horizontal, this produces 2 rows.
  crossAxisCount: 2,
  // Generate 100 widgets that display their index in the List.
  children: List.generate(100, (index) {
    return Center(
      child: Text(
        'Item $index',
        style: Theme.of(context).textTheme.headline5,
      ),
    );
  }),
);