Gallery and Media Attachments

Hi,
I would like to ask about your tip to create a gallery:

Tip: to create the gallery please use attachments from the Media library.

Could someone explain me how the images are attached to the page?

Thanks,

If You upload images from a certain page instead of main media manager, then they are "attached" to that page. Same goes for posts.

Cool, thanks for quick reply. Is it possible to attach already uploaded images(from media library)?
How can I unattach them?

Sorry, but WordPress doesnt allow that. But You could search for a plugin that makes this possible:
http://wordpress.org/extend/plugins/unattach/
but I havent tested it.

Thanks, it looks like Wordpress standard gallery option is more flexible and user friendly.