style-plugin-collection.css There have all CSS plugin files.
style.css used for theme style CSS.
responsive.css used for mobile device supported.
jquery.1.12.4.min.js is a stable version of jQuery which is required to place upon all scripts otherwise none of the jquery code will work.
bootstrat.min.js is used as the core of this template. It is a widely used resource in today’s era. Used to make this template responsive and providing all main classes for ui and also provides scripts that helped to form these templates.
contact-form.js is a jQuery plugin used for contact form data validation.
main.js is a custom jQuery used for active all jQuery file.