Application is a set of host items. For example, application 'MySQL Server' may contain all items which are related to the MySQL server: availability of MySQL, disk space, processor load, transactions per second, number of slow queries, etc.
An item may be linked with one or more applications.
Applications are used in Áú»¢¶Ä²© front-end to group items.
Currently a host cannot be linked to different templates having same application.