Netflow settings in out question

Netflow settings in out question

Hi - All,

what are the correct settings to enable NetFlow in Cisco IOS device? In this case,
if I have one switch and all traffic will through this switch.
does it mean I need to enable all of the interface (ingress) to capture correct traffic? https://pitstop.manageengine.com/portal/community/topic/in-out-traffic-issue I saw NetFlow dashboard has source and destination option and both of them have in and out option as well.
can anyone explain what is the difference between source -> in and source -> out?
and what is different between destination -> in and destination -> out?

Thank you! Code Chang