full_file_name = os.path.join(src, file)

This line of code joins the `src` directory path and the `file` name to create the full file path. It concatenates the two strings using the appropriate file path separator for the operating system. For example, on Windows, this would use backslashes (\) as the separator, while on Unix-based systems it would use forward slashes (/).

The resulting `full_file_name` variable would contain the full path to the file, which can then be used to perform operations on that file, such as reading its contents or copying it to a new location.