sudo iptables -t nat -A POSTROUTING -o enp0s3 \ -j SNAT --to-source 10.0.2.7

This command adds a rule to the NAT table of the iptables firewall configuration. The rule specifies that any outgoing traffic (-o) from the enp0s3 network interface should have its source address changed (-j SNAT) to 10.0.2.7 (--to-source 10.0.2.7). SNAT stands for Source Network Address Translation, which is a technique used to change the source IP address of outgoing traffic to a different IP address. This can be useful in scenarios where the original source IP address is not recognized by the destination network, or if the source IP address needs to be hidden for security reasons.