AEM Licenses

Hi all,

As you are all aware, AEM could be used just as a front end to some other tool. Ex: AEM could front end Hybris.

AEM could also be used just as a back end, making it headless.

How is AEM Licensed? As a number of front ends or number of back ends or not by these two, but by some other parameter like number of Author users?

Kindly reply ASAP.

Thanks,

Rama.