An item is an individual metric.
Items are used for collecting data. Once you have configured a host, you must add items to get actual data. One way of quickly adding many items is to attach one of the predefined templates to a host. However, for optimized system performance, you may need to fine-tune the templates to have as many items and as frequent monitoring as necessary.
To specify what sort of data to collect from a host, use the item key. For example, an item with the key name system.cpu.load will collect processor load data, while an item with the key name net.if.in will collect incoming traffic information.
Additional parameters can be specified in square brackets after the key name. For example, system.cpu.load[avg5] will return the processor load average for the last 5 minutes, while net.if.in[eth0] will show incoming traffic in the interface "eth0".
See individual sections of item types for all supported item types and item keys.
Proceed to creating and configuring an item.