Third-party vendor services include traffic redirection, load balancer, and guest security services such as data loss prevention, anti virus, and so on. Service Composer enables you to apply these services to a set of vCenter objects.
A security group is a set of vCenter objects such as clusters, virtual machines, vNICs, and logical switches. A security policy is a set of Guest Introspection services, firewall rules, and network introspection services.
When you map a security policy to a security group, redirection rules are created on the appropriate third-party vendor service profile. As traffic flows from virtual machines belonging to that security group, it is redirected to registered third-party vendor services that determine how to process that traffic. For more information on Service Composer, see Using Service Composer.