Conceptually, bar coding and RFID are quite similar; both are intended to provide rapid and reliable item identification and tracking capabilities. The major differences are :
The possibility to WRITE, or update the memory content identifying an object. Barcode content cannot be modified.
The tags unique identifier cannot be copied, unlike barcode.
The label doesn't have to be visible as information is carried by radio-frequency. Barcodes, on the other hand, must be very clearly visible, in order to be read.
Because of the low cost of bar code labels, established standards, and global deployment, bar coding is widely accepted while, in general, RFID has been limited to niche applications.
There are different bar code symbologies in use today, there are different RFID standards regarding the way data is captured from tags-the RF communications protocol.