Website user password verification
You really don't need two queries to do this. You can just use your second query, and if it doesn't return any results, report that. Eg:

$stmt = $conn-&gt;prepare("SELECT pw FROM Users WHERE email = ? LIMIT 1");
$stmt-&gt;bind_param('s', $email);
$stmt-&gt;execute();
$result = $stmt-&gt;get_result();

if(mysqli_num_rows($result) == 0){
    echo "Email has not been registered yet";
}

$pwHashed = $result-&gt;fetch_assoc();
if(password_verify($pw, $pwHashed["pw"])){
    echo "Password correct";
}else{
    echo "Password incorrect";
}  


Other than this, your code looks good. You use prepared statements, so it's secure, and your style is consistent and easy to read. I would probably write pw as password as it's more readable, but otherwise everything looks good.