user-interface

 User interface , often abbreviated as UI, formerly called human interface ( HI ), refers to presentational and interactive design elements of potentially any tool, but usually electronic tools, specifically their hardware and/or software.

A user interface is also often referred to in context simply as an interface, or implied when used as a compound noun with some user-level concept or object, e.g.:
 * post and posting interface
 * edit and editing interface
 * comment and commenting interface
 * admin and admin interface