The word small business conjures images of mom-and-pop shops, local restaurants, and independent contractors. And that’s exactly what they are: they’re a vital part of the nation’s economy and a major driver of economic growth. There are 30.2 million of them in the U.S., according to the Small Business Administration’s Office of Advocacy. They employ millions of people and contribute to a wide range of communities’ unique cultural characteristics.

But just what makes a small business? The official definition comes from the Small Business Administration and varies by industry. In general, a small business must have fewer than 500 employees and gross less than $5 million in a year to qualify. But those numbers can be adjusted to account for a business’s special circumstances, such as the size of an individual location or the number of small businesses in a specific geographic area.

Regardless of the size of a business, entrepreneurs must start their ventures with a solid plan. This includes a business model outlining who the company serves, its products and services, how it meets customer needs, and a financial plan that covers startup costs, revenue projections, and funding strategies. Choosing the right business structure is also essential. A limited liability corporation (LLC) is a popular choice among small businesses, as it provides personal asset protection and tax flexibility.

If you need money to start or grow your business, be sure to check out federal, state, and local programs. And if you need an extra boost, consider seeking out Small Business Investment Companies (SBIC). These private investment funds use their own capital and funds borrowed with an SBA guarantee to make equity and debt investments in qualifying small businesses.