Simple Network Management Protocol (SNMP) is used in network management systems to monitor network-attached devices for conditions that warrant administrative attention.
A managed device can be any piece of equipment that sits on your data network and is SNMP compliant. Routers, switches, hubs, workstations, and printers are all examples of managed devices.
An agent is typically software that resides on a managed device. The agent collects data from the managed device and translates that information into a format that can be passed over the network using SNMP.
A network-management system monitors and controls managed devices. The networkmanagement system issues requests, and devices return responses.