What are the potential consequences of not knowing the PHP version on a server and how can this information be crucial for development?

Not knowing the PHP version on a server can lead to compatibility issues with code that relies on specific PHP features or functions. This information is crucial for development to ensure that the code runs smoothly and efficiently on the server. To determine the PHP version on a server, you can use the `phpversion()` function in PHP.

$php_version = phpversion();
echo "PHP Version: " . $php_version;