The aggregate domain pattern is related to the object's life cycle, and defines ownership and boundaries.
When you reserve a table at your favorite restaurant online using an application, you don't need to worry about the internal system and process that takes place to book your reservation, including searching for available restaurants, then for available tables on the given date, time, and so on and so forth. Therefore, you can say that a reservation application is an aggregate of several other objects, and works as a root for all the other objects for a table reservation system.
This root should be an entity that binds collections of objects together. It is also called the aggregate root. This root object does not pass any reference ...
