While a barcode only holds information in the horizontal direction, a QR code does hold information in both horizontal and vertical directions. Due to this, a QR code holds hundreds of times more information than a barcode.
With that being said they have different purposes, and there about the same developed as each other, unless you count how much information they can store.
A Storage Area Network (SAN) is a high-speed sub network of shared storage devices. A SAN's architecture works in a way that makes all storage devices available to all servers on a LAN or WAN. As more storage devices are added to a SAN, they too will be accessible from any server in the larger network.
