CMS2CMS offers you the opportunity to choose between the installation of the Connector Plugin/Extension or the Connection Bridge. Thus, there are two paths you can go by, select the one you are more comfortable with.
The main difference between these two methods of setting up the connection is that the Connection Bridge file needs to be installed via FTP server, while the Connector Plugin/Extension has to be uploaded to your website through the admin panel.
CMS2CMS Connector Plugin is designed to establish the connection between CMS2CMS software and your WordPress website. It can be used when migrating your content to or from WordPress CMS. You can find more details about installation this plugin here.
The purpose of the CMS2CMS Connector Extension is to establish the connection between your Joomla website and CMS2CMS software. It can be used when migrating your content to or from Joomla CMS. More information on installation and usage of this extension you can find here.