can i edit pages of a site not built with elxis?

[markkis]

and do I need a database to use Elxis?

[Farhad Sakhaei]

You can edit any page you like , Add many pages beside Elxis , But if you added a page without using Elxis , You should try to edit it by using a code editor (Dream Weaver , Front Page , CoffeCup , ... What ever you want)

I recommend you to use autonomous pages in Elxis rather than this way ...

and do I need a database to use Elxis?

Yes , You need a MySql database or Postgres

[rentasite]

and do I need a database to use Elxis?

You have a site, and you want it to work with Elxis. Correct?