There is a history that is maintained to store the information of the two entities that are related to each other and are already synchronized. This also keeps the information about the entity that is last updated on the server. This information is required to keep the link between the two always synchronized. This will help in not loosing any data and maintaining tasks, appointments and contacts as synchronized entities. It is very necessary for a large system to keep the data preserved. The syntax of the history file will be given as follows:

<ProfileName>his<EntityName>.syc

Where EntityName in {“app”,”tsk”,”cont”}