Each SNMP object is defined to have a particular access, either read-only, read-write, or write-only, that determines whether the user can read the object value, read and write the object (with a set command), or only write the object.
Before any object can be read or written, the SNMP community name must be known. These community names are configured into the system by the administrator, and can be viewed as passwords needed to gather SNMP data. Community names allow reference to portions of the SNMP MIB and object subsets. The purpose of these values is to identify commonality between SNMP object sets, though it is common practice to make these community names obscure to limit access to SNMP capability by outside users.