The basic difference between business and employment visa is:
A Business Visa is given to those foreign nationals who wish to travel to India to promote, establish, or negotiate business-related activities in India. Even people who want to establish contact for future business relations are allowed to travel on this Visa. Large manufacturing companies and engineering establishments, etc. use Business Visas to send their representatives or salesmen or executives to the country to promote and sell their goods or buy large quantities of Indian-made products.
An Employment Visa in India is issued to those foreign nationals who wish to travel to India in order to be employed by a business concern or NGO functioning in India. The intention of these Visa applicants is not to establish business communication or establish a business itself in India, but to contribute their knowledge, skill, and experience in a professional capacity to an existing business, NGO, corporation, etc. or for the completion or execution of projects.