To provide a great eCommerce solution with many great pre-built features, Magento has created its own modules.
When you run the following command:
php bin/magento module:status
Magento shows the list of all modules with the respective status of the modules, even if it is a third party module or its own module.
All modules of Magento core start with
Magento_. Apart from that, Magento time to time includes custom popular functionalities in the newer versions. For example Amazon Pay etc. When such third party solutions become part of Magento, they also become in the list of modules. These modules can be found under
/vendor/<module_package>, for example
In a nutshell, don't worry about the modules in the list you have not installed. These may be part of default Magento functionality.
To be sure, you can match it with the default Magento with the same version.
I hope it should be helpful.