How to find out available modules?

[Jose Albores.]

Hi everybody... and thanks again for everyone who helps us with our
first-linux-steps.
Today, my question is:
Is there any command/way to find out which 'supports' have been loaded
as modules???
E.G.: if I want to find out the packages installed with '.rpm' I send
the command:
        $ rpm -qa
Then...
How can I know which are the modules availables after my kernel
compilation???
TIA.

--
José Albores
Buenos Aires.
Argentina.