Which parameter must be unique when adding an Item to a Host in Zabbix?

In Zabbix, when adding an Item to a Host, the Key parameter must be unique. The Key serves as a unique identifier for the Item and distinguishes it from other Items within the same Host. This ensures that each data point collected from the Host can be accurately referenced and monitored without confusion.

Having a unique Key is vital because if two Items have the same Key, Zabbix would struggle to interpret which data to collect or display, leading to potential data conflicts or loss. Thus, while Item Name and Description can be the same across different Items, the Key must be distinct to maintain clarity and efficiency in data collection and monitoring.