Which mac level has the highest level of security?

all macs have the same level of security
but to be extra sequre and encrypt your local hard drive go to system_prefererences>security_and_privacy then turn on filevault
also to be extra secure restart your computer while holding down alt/option then selct recovery wait for it to start up and then select utilities and then firmware password. also encrypt usb sticks by right clicking on the drive and then select encrypt