Not easy to learn. Water purifier, also known as water purifier and water purifier, is a water treatment equipment that deeply filters and purifies water quality according to water requirements. The water purifier usually refers to a small purifier used in the family. After the purifier is sold, you need to know the advantages and disadvantages of the purifier, the installation and debugging of the equipment, and the maintenance and use of the equipment. It is very difficult to learn to make corresponding clean drinking water plans according to customers' needs. After-sales service refers to a series of services provided by manufacturers and distributors to consumers after selling their products (or services), including product introduction, delivery, installation, debugging, maintenance, technical training and on-site service.