Destination NAT: This rule type allows you to change the destination IP address of a packet from an external IP address to an internal IP address. You can use this rule type to provide access to your internal servers from external networks using public IP addresses.
Source NAT: This rule type allows you to change the source IP address of a packet from an internal IP address to an external IP address. You can use this rule type to provide access to external networks from your internal servers using public IP addresses.