Hi Team,

I see the Apex mentioned below in my org,
ForgotPasswordController
LightningForgotPasswordController
LightningLoginFormController
LightningSelfRegisterController
ChangePasswordController
CommunitiesLandingController
CommunitiesLoginController
CommunitiesSelfRegConfirmController
CommunitiesSelfRegController

It has corresponding Visual force and Aura components.

It looks like they are automatically generated by sfdc.com.

I am not sure under what circumstance do they get generated? Any suggestions?
Where can I find the description for those Apex, Aura and Visual Force Lightning components?

Many Thanks in advance!