I am pretty new in WP and I have the following doubts about work that I have to do.
I have to create a multisite (3 sites related together) starting from 3 separated old WP websites.
I know that some years ago there was WordPress MU that performed this task but reading the online documentation it seems to me that now WordPress MU is a closed project and that the multisite functions is natively implemented by the standard WordPress version, is it true?
So, if the previous assertion is true, can I do the following?
Use WP to create a multisite that implement 3 different sites (each one with a unique theme, widgets and configuration)
Take the posts of the previous old WP website and import it in the related new single site of my new multisite.
Can I do this things?