Source NAT changes the source address in IP header of a packet. It usually use for packets leaving your network.
Destination NAT changes the destination address in IP header of a packet. It usually use to redirect incoming packets with a destination of a public address/port to a private IP address/port inside your network.
On source NAT rule, I only need to configure a singe way out, and the return packet will be make use of the previous session to coming in, ie
original source translated source
1. packet from 192.1681.x leaving the network to a 184.108.40.206 (destination) will do the source NAT translation :
2. return packet from destination 220.127.116.11 to source 203.193.84.y
#2 has not created on firewall but it can relate #1 rule to coming it, correct ?
Same concept also apply to destination NAT, correct ?