A large business is generally defined as a business that has more than 500 employees. But there are a few exceptions. The definition of a large business can also depend on the industry it is in, the amount of revenue it brings in, and the amount of money invested in it.
In the US, the Small Business Administration (SBA) defines a small business as one that has fewer than 500 employees, but it can make exceptions for businesses that are in certain industries. For example, companies that are primarily involved in retail or manufacturing may be allowed up to 1,500 employees or more before they are classified as a large business.
In the United Kingdom, the Department for Business, Energy and Industrial Strategy classifies companies with 250 or more employees as a large business. They have special rules for companies with 10-50 employees, as well.
There are also different regulatory requirements for large businesses as compared to small businesses. For example, a large business may have to file more financial information and be subject to more strict accountability than a small business.
Finally, larger businesses have more resources to be able to handle bigger projects and employ more people. This allows them to serve a larger customer base, provide more services and products, and potentially bring in more revenue over the long term.
In summary, it can be difficult to clearly define what qualifies as a large business as each industry and country may have its own criteria. Generally, though, large businesses typically have more than 500 employees or significant revenue and investment.