Reading on how materialized views are materialized?

Where can I find some more detail? I am deciding between a flat table
populated for the current month only with a script versus a materialized
view, and I'd like to understand better if the latter is intelligently
being refreshed (meaning years of data won't be re-populated, only what's
changed).

Thanks.

--
Wells Oliver
wells(dot)oliver(at)gmail(dot)com <wellsoliver(at)gmail(dot)com>