Barcodes
One-dimensional barcodes such as Code 128, EAN and UPC are compact and common in inventory, retail and logistics.
QR codes
QR codes can hold more data in two dimensions and are commonly used for URLs, contact details, Wi‑Fi configuration and quick mobile scanning.
Which should you use?
Use the format required by the receiving system. For a consumer-facing link, a QR code is usually more convenient. For product identifiers and established scanning workflows, a standard barcode may be required.