Hi Ahmed,
Check this document, it wil answer msot of questions about PFC, DFC and CFC.
DFC does the forwarding based on information syncronized with supervisor, simply offloading the forwading to be done locally. It is supervisor engine that builds the forwarding tables and manages l2/l3 protocols (as well as many other things, starting with booting the cards and checking HW), so without it your switch/router would not run.
Kind Regards,
Ivan
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Kind Regards,
Ivan