When you download the software to your computer, it is to then install the software onto your server (web hosting account). Then you can create/manage your website from your website admin panel, from any computer with an internet connection. You can play around with the Demos online: https://www.ultimatewb.com/demolinks .
We do provide free professional software installation service with all UltimateWB web hosting packages here: https://www.ultimatewb.com/domain-names-web-hosting (still requires separate purchase of the software though). Alternatively, you can install the software yourself using the instructions/tutorial video on our website at https://www.ultimatewb.com/installation , or purchase the software install service on our website at https://www.ultimatewb.com/pro-services (when using the software on a server/web hosting account you buy elsewhere, that satisfies the Server Requirements, as listed here: https://www.ultimatewb.com/server-requirements ).