An object group is a collection of related objects that are grouped together for organizational or functional purposes. In computer programming, object groups can be used to organize code and data structures to make them more manageable and easier to maintain. In network security, object groups can be used to define access control lists (ACLs) and firewall rules by grouping similar objects together, such as IP addresses or port numbers. Overall, object groups help simplify complex systems and make them more modular, scalable, and effective.