NACL vs Security Group

Your VPC has a default security group with the following rules: Allow inbound traffic from instances assigned to the same security group. Allow all outbound IPv4 traffic and IPv6 traffic if you have allocated an IPv6 CIDR block. Your VPC has a default network ACL with the following rules: Allows all inbound and outbound IPv4 traffic and, if applicable, IPv6 traffic. Each network ACL also includes a non modifiable and non removable rule whose rule number is an asterisk. This rule ensures that if a packet doesn't match any of the other numbered rules, it's denied. [...]