Our themes on Themeforest are bundled in a .zip file that usually looks like themeforest-{some_number_here}-theme-name.zip. This bundle of joy contains demo content (the way our themes look on the preview server, including the sliders), documentation file, theme.zip, and sometimes child-theme.zip and .psd files of the theme when possible. Sometimes the theme designer gives the approval to pack the .psd files with the theme, sometimes they don’t.
Every theme can come with several included plugins. Usually that consists of visual page editor The Creator, portfolio plugin, testimonial plugin, subscribe plugin, Revolution Slider, Twitter scroller plugin, and others. Also some themes will recommend you to install plugins such as WooCommerce or Contact Form 7. It’s up to you whether you want to use them or not, but we recommend installing all the plugins that the theme requires, at least until you’ve imported the demo content, so that you don’t get any unnecessary errors while importing. Later you can remove, delete and do what ever you want – you paid it, no?