The key difference is whether you are paid in US for whatever you do. If it is a business meeting, you do not earn any income in US (your pay is in your home co

The key difference is whether you are paid in US for whatever you do. If it is a business meeting, you do not earn any income in US (your pay is in your home country). If it is work, it means that you are getting paid in US for something you are going to do here. Work visas need one of H or L categories ( or maybe something else). Business visas are the B1. The wording is ambiguous and not friendly to anyone (even to native English speakers), but that is government bureaucracy for you.