Visual Composer is a premium drag drop plugin that comes bundled with the theme. It provides 40+ elements that can be easily added to your page. In addition to extending functionalities of existing elements, Eva theme has added additional elements. With this set of elements, you will be able to create unlimited varities of pages.
Visual Composer documentation - https://wpbakery.atlassian.net/wiki/display/VC/Visual+Composer+Pagebuilder+for+WordPress
Visual Composer Video tutorials - https://vc.wpbakery.com/video-tutorials/
How to get the latest version of the plugin?
The Visual Composer plugin comes bundled with the theme. We'll always make sure to include the latest version in the main theme package so you can update yours.