How can data from external sources be properly processed and converted to the correct charset in PHP applications?

When processing data from external sources in PHP applications, it is important to ensure that the data is converted to the correct charset to avoid encoding issues. One way to achieve this is by using the `mb_convert_encoding()` function in PHP, which allows you to convert strings from one charset to another.

// Example code to convert data from an external source to the correct charset
$externalData = "Some data from an external source";
$correctCharsetData = mb_convert_encoding($externalData, 'UTF-8', 'auto');
echo $correctCharsetData;