What is the significance of the error message "Notice: Undefined offset" in PHP and how can it impact the functionality of a script?

The error message "Notice: Undefined offset" in PHP indicates that the script is trying to access an array element using an index that does not exist. This can impact the functionality of the script by potentially causing unexpected behavior or output. To solve this issue, you can check if the offset exists before trying to access it to prevent the error.

if(isset($array[$index])) {
    // Access the array element with the specified index
    $value = $array[$index];
} else {
    // Handle the case when the offset is undefined
    echo "Offset is undefined";
}