It is a plugin that restores the classic widgets interface in WordPress 5.0 and newer versions.

Here’s how the Classic Widgets plugin works:

1. Install the plugin through the WordPress plugin repository.
2. Once activated, the plugin restores the classic widgets interface in the Appearance > Widgets section of the WordPress dashboard.
3. Users can now use the classic widgets interface to add and manage widgets on their WordPress site.

Guidelines for using the Classic Widgets plugin:

1. The plugin is only intended for use with WordPress 5.0 and newer versions.
2. The plugin only affects the widgets interface in the WordPress dashboard and does not change any other aspect of the website.
3. Users should still be familiar with the basic concepts of widgets and how to use them on a WordPress site.

People use this plugin to restore the classic widgets interface that was present in previous versions of WordPress. This can be useful for users who prefer the classic interface, or for those who are more familiar with it. The plugin helps to simplify the process of managing widgets on a WordPress site, making it easier for users to add and configure the widgets they need.

The Classic Widgets plugin and the Classic Widgets Pro plugin are likely two different versions of a plugin designed to restore the classic widgets interface in WordPress 5.0 and newer versions. The main difference between the two is likely the features and level of support offered by each.

The Classic Widgets plugin is a free version that provides the basic functionality of restoring the classic widgets interface in WordPress. The Classic Widgets Pro plugin, on the other hand, is a paid version that may offer additional features and support. For example, the Pro version might include additional customization options, priority support, and access to updates and bug fixes.

The specific differences between the two versions of the plugin would depend on the specific plugin you are referring to. It is always a good idea to review the plugin’s documentation, and to compare the features and support offered by each version, to determine which one is the best fit for your needs.