Themes vs. Templates - Builder vs /zcms/editor

Hi Zoho Sites spport team.

Firstly: awesome website builder guys.

I created a new website a week ago and another website yesterday. The first site is significantly different to the new site in the back end and now refers to templates rather than themes. Additionally, the old site admin URL is https://sitebuilder-<#########>.zohositescontent.com/builder and the new one is https://sitebuilder-<#########>.zohositescontent.com/zcms/editor

Is this a new building/management system Zoho sites is moving to? If so, is there a simple way to move from one to the other, or would I need to rebuild from scratch?

Thanks, Peter