Tertiary industry refers to providing services. It is different from the primary and secondary industries which provide us with goods. Goods are tangible. This means they are physical things that you can touch, like a tomato or a car. Services are intangible. This means you cannot touch them.
Even though you cannot touch them, services are very useful. For instance, if you feel unwell you can go to a doctor. He or she will figure out what is wrong with you and tell you what you can do get better. A teacher will help you learn the knowledge and skills you need to be successful. The doctor and the teacher provide services. Some examples of services are shown below.