2 mysql entries into different tables in one query?

I know how to enter information into one table, but how would I enter or take information from 2 different tables at the s开发者_开发技巧ame time. I have researched and it has something to do with JOIN, but I have tried to no avail!

It is not possible to insert into 2 tables in one query.

(Technically - you can create a trigger in table A, that inserts something to table B, but in this case you're not able to control what data to insert from the INSERT)