In business, what's the main difference between a "customer" and a "client?"

Native speaker’s answer
Rebecca
A "customer" is someone who buys a product or something from a shop. A "client" receives a professional service from an individual or organization. A "client" can also be a regular customer, usually with set-up orders for the future. Ex: We haven't had many customers in our restaurant today. Ex: We signed a new client for event catering. Ex: My client wants to change the design.