Hi, RFC is Remote Function Call. Using this function module we can fetch the data from other system which is located some other place. Using T-code SM59 , you have to establish the connection between 2 systems .In one system you define function module and call this module in other system where you have to mention the key word 'DESTINATION ' besides function module name.
What are RFC's w.r.t SAP R/3 and how are they used?