Enable/Disable Extensions

mage2_module_commands

When you type bin/magento from base directory get these module options: 

module
 module:disable                            Disables specified modules
 module:enable                             Enables specified modules
 module:status                             Displays status of modules
 module:uninstall                          Uninstalls modules installed by composer

bin/magento module:status lists all the modules installed. You can see these in app/etc/config.php

bin/magento module:disable <module_name> to disable - this is effectively like changing to false in app/etc/modules/<module_name>.xml in 1.x

All its doing under the hood is commenting out or uncommenting the module name in config.php (open to view it)