What is the significance of JSON in AJAX requests and how was it utilized in the solution provided?

In AJAX requests, JSON (JavaScript Object Notation) is commonly used to transmit data between the client and server in a lightweight and easily readable format. It allows for the seamless exchange of data without the need to reload the entire page. To utilize JSON in AJAX requests, you can encode data on the server-side into JSON format before sending it back to the client, and decode JSON data received from the client on the server-side.

// Encode data into JSON format on the server-side
$data = array('name' => 'John Doe', 'age' => 30);
$json_data = json_encode($data);

// Send JSON data back to the client
echo $json_data;

// Decode JSON data received from the client on the server-side
$json_data_received = $_POST['json_data'];
$data_received = json_decode($json_data_received, true);

// Access the decoded data
$name = $data_received['name'];
$age = $data_received['age'];