We are creating lots of websites, and if each website has it's own CMS, then it's a problem with updating each website separately, harder to maintain, so I am interested how to create multisite? All sites could even use the same themes, for example partials (for example for showing team members, or logos of clients in predefined format).

Can you give steps how to do it? I found one article, but it describes only in general: https://rocketmedia.com/blog/building-a-multi-site-template-system-with-statamic

Also in this case is one licence enough, or I still have to buy licences for each site?