In the previous section, we discussed the available storage options for EC2 instances. The next step to launching our instance is to create a security group. In this section, we're going to show you how to create a security group, add rules, and complete the launch of our instance.

Now we've reached step 6 of launching our instance: configuring the security group.

Security groups allow us to protect our instance with firewall rules. We can allow traffic into our instance by protocol and source. Note that we have to have a security group associated with our instance. A security group could be associated with more than one instance.

So, for example, we can create a single security group for all of our web server instances if we would like. All traffic is implicitly denied by default. So, if you don't specify a rule for a particular protocol, then that...