ELS uses a publisher/subscriber paradigm to present a collection of logical libraries from a local publisher to a subscriber, or back-up. The subscriber may be local, with all storage devices attached, or remote using another ELS instance operating as a Subscriber Listener.
Each logical library may span multiple storage devices. This is the same approach used by modern media streaming systems, such as Plex, but is also useful for anyone producing large volumes of content, videos, music, images, data, etc. Each storage Location may specify a "Minimum Free Space". A library is defined as a Bibliography of Sources used by the library.
ELS may be run in a variety of modes. The visible mode is this ELS Navigator. However, several other command line modes are available to automate ELS operations. ELS started as a command line back-up tool. The addition of the Navigator desktop application in Version 4 added significant functionality.
The Browser presents a publisher and subscriber in a drag 'n drop interface. Selections made in the Browser are used by the Tools and Jobs. Selections may be changed while working with Tools and Jobs, e.g. using the Duplicate Finder select the Publisher and click "Run ...", then select the Subscriber and click "Run ..." again.
The Publisher and Subscriber tabs present the logical library structure. The System tabs present that computer's entire directory tree.
Various Tools are provided to make building and maintaining libraries easier. The Duplicate Finder and Empty Directory Finder are used manually. The other Tools may be run by themselves or combined into Jobs.
Jobs are combinations of one or more Tools. Jobs are composed of Tasks which are a Tool with selections for the publisher and subscriber.
The System menu contains advanced features for security and Hint processing.