I would argue startups are a specific subset of businesses that initially are "Small Businesses" with the defining quality being the capability to scale to something much larger, obviously when faced with a market opportunity that allows it do so (whether that market is existing or is completely new).
Of course, the "term" startup is often used loosely but most often is used to define the usual: Tech-oriented, "innovative" businesses seeking to raise millions of dollars and eventually become companies that can make hundreds of millions of dollars (or billions) and can make the large exit (as PG pointed out above).
Of course, the "term" startup is often used loosely but most often is used to define the usual: Tech-oriented, "innovative" businesses seeking to raise millions of dollars and eventually become companies that can make hundreds of millions of dollars (or billions) and can make the large exit (as PG pointed out above).