Access policies are objects that you attach to entities and resources to define their
permissions
Roles are created and then “assumed” by trusted entities and define a set of permissions for
making AWS service requests
Security groups and network ACLs are used as instance-level and subnet-level firewalls
respectively
Key pairs are created in EC2 and are used to login to EC2 instances. Don't confuse these
with access keys and secret IDs which are used to grant programmatic access to resources