Database connection handy including

[NetLancer]

Hi there! I've been looking for a convenient method of including $db_connection just whenever needed and i've come up so far with confinement of DNS in predefined class.
Then each time i need it do: $f3->call('DBClass::connect'), but still it seems to me somewhat awkward.
Now i see in the project's index.php file:
// database connection used by app [lines 35-36]
$dbConfig = $f3->get('db'); -which seems handy enough,
but keep on guessing what it actually referencing so i can make use of.

Pardon my dummy question, but i don't see the other way to post a question of this sort, hope for simple answer :)