Nautilus Terminal is a plugin for Nautilus, it always open terminal in Nautilus at current folder, and follows the navigation (like an automated "cd" command). This plugin also supports drag and drop folders and files.
It is possible to hide and show terminal via this shortcut - F4
If you don't want to install this plugin, there is alternative for you called Sunflower. Sunflower is twin-panel file manager.
To install Nautilus-Terminal in Ubuntu/Linux Mint open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:
Now restart nautilus