PHP extensions are additional modules that expand the core functionality of PHP on your web hosting server. Think of them as plugins or add-ons that enable specific features your website or application needs to run correctly. Without the proper extensions, your PHP scripts might fail or display errors.

When choosing a web hosting plan, it's crucial to ensure it supports the necessary extensions. Common essential extensions include:

• MySQLi or PDO: For connecting to MySQL databases.
• cURL: For transferring data with various servers using URLs.
• GD Library: For dynamic image creation and manipulation.
• OpenSSL: For secure HTTPS connections and data encryption.
• ZIP: For creating and extracting compressed archive files.

To check which extensions are active on your server, you can create a simple PHP file with the code <?php phpinfo(); ?> and run it. If you find a missing extension, contact your hosting support team—they can often enable it for you. Always verify extension requirements for software like WordPress, Joomla, or custom applications before installation to avoid compatibility issues.