A customer is someone who buys goods or services from a business or store. When you walk into a bookstore and purchase a novel, you're a customer. When your parents order pizza for dinner, they're customers of the pizza restaurant. The store owner or business wants to keep customers happy so they'll come back again and again.

That idea of habit explains why businesses care so much about customer service: treating people well, answering questions patiently, and solving problems quickly. Good customer service turns a one-time buyer into a regular customer who returns again and again.

Understanding customers matters whether you're running a lemonade stand or a giant corporation. You have to think about what customers want, what they can afford, and how to make their experience pleasant. A successful business owner knows that without customers, there is no business. Even kids selling cookies door-to-door or offering to mow lawns are learning to think like business owners: every neighbor who might buy is a potential customer worth treating with respect and care.