Bapat
When memory is displayed this way the first number represents the amount of memory available for general processing (the executing code, routing table, process stacks, OSPF Link State Data Base, EIGRP topology table, ARP table, interface IDB information, NAT table, and things like that) and the second number is the amount of memory for I/O and packet memory which is used for data packets as they are recieved, processed, and forwarded to their destination.
So the short version of the difference is that the first number is general memory for processing and the second number is packet memory.
HTH
Rick
HTH
Rick