can one explain me how PAM authentication work when i use key based authentication for login ?

[parag]

i am using only key based authentication . i went through different articles and as per those , PAM does not come in picture when we use key based authentication .
so if this is so , which setting decide "do not use pam if there is key based authentication"

below is my sshd config setting ::

# Enable public key authentication
PubkeyAuthentication yes


# Never use host-based authentication. It can be exploited.
IgnoreRhosts yes
IgnoreUserKnownHosts yes
HostbasedAuthentication no

# Enable PAM to enforce system wide rules
UsePAM yes

 

[HostechSupport]

You can combine ssh public key authentication with PAM authentication. The ssh daemon will do the public key authentication and the password authentication or OTP/GA authentication is managed via PAM. SSH daemon decides to use pam or not.