Hello Aneesh,

A Management Information Base (MIB) is a collection of information that is organized hierarchically. MIBs are accessed using a network-management protocol such as SNMP. They are comprised of managed objects and are identified by object identifiers.

An object identifier (or object ID) uniquely identifies a managed object in the MIB hierarchy. The MIB hierarchy can be depicted as a tree with a nameless root, the levels of which are assigned by different organizations.

Please refer the below URL for some additional details.

http://www.cisco.com/en/US/docs/internetworking/technology/handbook/SNMP.html

Regards,

Arul

*Pls rate if it helps*