Ultrasonic flow meters are devices that help calculate the flow of water by measuring the velocity of the liquid by using ultrasound. Ultrasonic flow meters are extremely useful as they particularly help in measuring the flow of waste water.
In terms that are more common, we can refer eCommerce as the platform for buying and selling of products and services through business and services over internet. In a simplest form people use this term as online shopping. Both the terms means one and the same thing.