An ECR or electronic cash register is a physical device that combines a secure cash box, transaction tallying, and receipt printer into one operating unit. A point-of-sale (POS) system, on the other hand, is a combination of software and hardware that centralizes sales, payment processing, and customer relationship management (CRM). ECRs are best for businesses that only need a device to ring up their sales and print receipts, whereas a POS system offers many more advanced features and tools. Most businesses will use a combination of both physical ECR hardware and POS technology for maximum functionality.