With SPENGO+Kerberos authentication, the SWITCH edu-ID IdP trusts the Windows PC authentication. This means that a user who has logged in on a Windows PC does not have to log in again on the edu-ID IdP.
SPNEGO+Kerberos authentication is currently under development.

SPNEGO+Kerberos login can only be set up for entire organizations for their domain joined computers. Check out the documentation to set it up for your organization.