Salesforce Lightning Experience is a user interface that is modern, fast, and intelligent, and it is built on established Salesforce1 Mobile APP technology. To construct modern corporate APPLICATIONS, it INTEGRATES the Lightning Designing System (LDS), Lightning App Builder, and Lightning Components. Salesforce Lightning Experience is a next-generation productive user interface for Salesforce.com's sales and supports staff. Salesforce.com has introduced Salesforce1 for mobile applications, as well as two user interfaces for desktop versions of Salesforce traditional and lightning Salesforce.

Lightning Experience (or LEX for short) introduces a completely new client-side architecture, DEPARTING from the server-side rendering given by its predecessors (Salesforce Classic) and Visualforce. Visualforce UIs can still be used with Lightning Experience for backwards compatibility, but they won't have the same amount of extensibility or visual appeal as custom UIs DESIGNED with the Lightning framework.