A startup is, by my definition, something new – something the world has not seen before. Startups almost include science or technology, and some innovation. It’s risky because the business model is unknown. The founders (the people who create a startup) are looking for a business model that will work.
Founders are not the same as small business owners.
The person who starts a small business uses a known business model, and a familiar product or service. This could be as common as opening a coffee shop or a certified public accountant hanging out a shingle. Business owners face risks, too, but the risks are different.