This document discusses business sizes and their impacts. It defines micro, small and medium, and large businesses based on employee count. Small and medium enterprises (SMEs) are defined as having between 0-249 employees. SMEs make up over 96% of companies in the US and EU and account for a significant portion of employment and value added. The document also discusses statistics on SMEs and their impacts in countries like the UK, US, and Vietnam. SMEs play an important role in job creation, innovation, and economic growth through competition and knowledge spill-overs.