Those are orthogonal classifications. Startup is an early stage company, bootstrapping income/revenue flows. Small business is well... small, usually in terms o

Those are orthogonal classifications. Startup is an early stage company, bootstrapping income/revenue flows. Small business is well... small, usually in terms of money flows and number of employees. In contemporary usage "tech startup" usually means an early stage company expected to relatively quickly grow their money flows and have high opex-to-capex and incoming-to-outgoing transaction ratios.