How can I tell if my website is running Gantry5

Gantry 5 was made from the ground up to make life easier for both the developer and the user. Themes made with Gantry 5 share a consistent user experience, reducing the learning curve for both parties. So, whether you are managing one site or fifty, the process for managing your theme is the same no matter how many different themes you use. Gantry is a theming framework. If your website is a house, then the content management system CMS is the foundation. This is where your data is stored and managed. It is the system you use to add content such as posts, articles, pages, images, and more. Gantry currently works on three content management systems, including: WordPress,  Joomla, Grav. You can right click and view the page source to find if the Gantry is mentioned probably on the home page or sub site pages.