$mail

A simple one!

$mail is a variable in PHP that is commonly used to send emails using the PHP mail() function or a third-party library like PHPMailer.

Here's an example of how you might use $mail to send an email:

$mail = new PHPMailer();
$mail->isSMTP();
$mail->Host = 'smtp.example.com';
$mail->Port = 587;
$mail->SMTPAuth = true;
$mail->Username = '[email protected]';
$mail->Password = 'your_password';

$mail->setFrom('[email protected]', 'Your Name');
$mail->addAddress('[email protected]', 'Recipient Name');
$mail->Subject = 'Test Email';
$mail->Body = 'This is a test email';

if (!$mail->send()) {
    echo 'Error sending email: '. $mail->ErrorInfo;
} else {
    echo 'Email sent successfully!';
}

In this example, $mail is an instance of the PHPMailer class, which is used to send an email to a recipient. The email is configured with the sender's email address, recipient's email address, subject, and body. If the email is sent successfully, a success message is displayed. If there's an error, an error message is displayed with the error information.