Salesforce Lightning is a group of technologies and tools that are behind an important upgrade to the Salesforce platform. Salesforce lightning contains the following components:
Lightning Component Framework: It is a javascript framework and a collection of general components that allow us to develop the recyclable components for personalizing the Salesforce1 Mobile App, and Lightning Experience.
Experience: It relates to a set of advanced user interfaces that we optimize for speed.
Lightning Exchange: It relates to a part of AppExchange where we find more than 70 partner components to start the development.
Lightning Design System: It relates to the best practices and style guides of advanced enterprise UX to build pixel-perfect apps.
Visual Building tools: It relates to drag-and-drop technologies for easy and quick customization and app building.