Cisco Systems: Object Groups for ACLs

Object Groups for ACLs [Cisco IOS Software] - Cisco Systems
The Object Groups for ACLs feature lets you classify users, devices, or protocols into groups and apply them to access control lists (ACLs) to create access control policies for those groups. This feature lets you use object groups instead of individual IP addresses, protocols, and ports, which are used in conventional ACLs. This feature allows multiple access control entries (ACEs), but now you can use each ACE to allow an entire group of users to access a group of servers or services or to deny them from doing so.
In large networks, the number of ACLs can be large (hundreds of lines) and difficult to configure and manage, especially if the ACLs frequently change. Object group-based ACLs are smaller, more readable, and easier to configure and manage than conventional ACLs, which simplifies static and dynamic ACL deployments for large user access environments on Cisco IOS routers.
Cisco IOS Firewall benefits from object groups, because they simplify policy creation (for example, group A has access to group A services).