Kerberos and SideCar are bundled together in the SideCar installer. SideCar is the utility that is always running on your computer, waiting for you to request a Kerberos ticket to authenticate your identity. When you need a Kerberos ticket, SideCar automatically prompts you for the information that Kerberos needs in order to connect.
Please note that after you install SideCar, you will need to reboot your computer in order for SideCar to be active.