How can different PHP versions affect the interpretation of code and lead to syntax errors like unexpected T_INCLUDE?

Different PHP versions can have varying syntax rules and features, leading to code written for one version to produce syntax errors on another. To avoid unexpected T_INCLUDE errors, make sure to use the correct syntax for including files in PHP. This can be achieved by using the `require` or `include` statements followed by the file path in quotes.

// Correct way to include a file in PHP
require 'path/to/file.php';