Getting username out of a database to put in another

Well I've 2 databases, one with the users information(id, name, password). And one database with some other optional stuff. To add something to a list.(name of group, short description, long description and also the username).

Is it possible to get the username out of database one and put it into database 2. Or should I use just one database?

I need to get the username, name of the group and short description in one html class.

it is related information and does not belong in separate databases, unless you mean separate tables.

it is related information and does not belong in separate databases, unless you mean separate tables.

Well the information is sort of related, far from all the users will make us of the "second database" so. It still should be in one database I guess, it doesn't mind far from all make use of it?