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Files (also known by its former name, Nautilus) is the official file manager for Gnome. It has an emphasis on being intuitive and simple, and follows the Gnome Human Interface Guidelines.
Specs
Pros
Pro Widely supported
The program is distributed as a single source archive, which can be configured, compiled and installed on almost any Linux flavor. There are no binary files for a specific Linux distribution, but you can install it directly from the default software channels of your operating system.
Pro Allows you to access remote or local locations
On recent versions of GNOME, you can click the Files entry in the panel to access a specific location (remote or local), connect to a certain server (FTP, SFTP, SAMBA, etc.), access your bookmarks, open a new window, as well as to change its default functionality.
Pro Easy to use and familiar user interface for Ubuntu users
The user interface of Files is very familiar to Ubuntu users, most probably because Canonical still uses Nautilus (an old version of it) as the default file manager for its world’s most popular free operating system, Ubuntu Linux.
It split into two parts, a sidebar and the main file viewer. While you already know what the latter can do for you, the sidebar offers quick access to Places, Devices and Network locations, as well as any other bookmarks that you can add whenever you want.