What does $row stand for in prepared statements (MySQLi)? - php

Question

I'm watching a login system guide on Youtube, and recreating it. It's about done, but every time i try to login, it gives me an error:
"Incorrect Password"
I suspect this has to do with the $row that was made in an if statement. But i don't know what $row does.
I'll leave some code if someone can see the problem.
<?php
else {
$sql = "SELECT * FROM users WHERE uidUsers=? OR emailUsers=?;";
$stmt = mysqli_stmt_init($conn);
if (!mysqli_stmt_prepare($stmt, $sql)) {
header("Location: ../index.php?error=sqlerror");
exit();
}
else{
mysqli_stmt_bind_param($stmt, "ss", $mailuid, $mailuid);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
if ($row = mysqli_fetch_assoc($result)) {
$pwdCheck = password_verify($password, $row['pwdUsers']);
if ($pwdCheck == false) {
header("Location: ../index.php?error=wrongpwd");
exit();
}
elseif ($pwdCheck == true) {
session_start();
$_SESSION['userId'] = $row['idUsers'];
$_SESSION['userUid'] = $row['uidUsers'];
header("Location: ../index.php?login=succes");
exit();
} ?>

Answer 1

if ($row = mysqli_fetch_assoc($result))
This tries to fetch a row from the query result. If there is a row to fetch from the results, then that row is assigned to the $row variable and the if statement is executed. If there is not a row to fetch from the results, then the if statement returns false and is skipped.