What is the difference between barcodes, QR codes, and RFID?

All three solve the same problem, attaching a machine-readable identity to physical stock, with different trade-offs. Linear barcodes (UPC, Code 128) are the cheapest and most universal. Labels cost fractions of a cent, every scanner and phone reads them, and supplier packaging usually arrives with one printed on. Limits: small data capacity, line-of-sight scanning, and damaged labels don't read. QR codes hold far more data, scan quickly from a phone camera at any orientation, and tolerate partial damage. For internal use (bin labels, asset tags, kit labels) they're often the better print, since teams scanning with phones rather than dedicated guns get faster reads. A QR can also encode a URL that opens the item's record directly. RFID changes the physics: tags answer a radio reader without line of sight, so a handheld sweep can count a shelf in seconds and a dock portal can read a whole pallet. The costs are real, though: tags run from a few cents to dollars each, readers cost hundreds to thousands, and metal and liquid environments interfere. RFID pays off at high volumes, on high-value items like tools and IT assets, or where counting speed is the bottleneck. The practical default for most operations: barcodes or QR codes plus phone scanning, with RFID reserved for the specific category that justifies it.