You can come to the United States to participate in a specific exchange visitor program approved by the United States Department of State (formerly the U.S. Information Agency (USIA).
United States Department of State has accepted a vide range of such specific programs, sponsored by schools, businesses and a variety of organizations and institutions, meant to promote international collaboration through exchange of information. These programs are envisioned for trainees, scholars, students, in business and industry, international visitors, teachers, research assistants and on cultural missions.
You can work with permission in the United States if work is part of your approved program or if you are given authorization to work from the official program sponsor.
You can move in and out of the United States or stay in the country until the conclusion of your exchange visitor program. Visas are obtainable for relatives accompanying you to the United States. Your accompanying relatives can work in the United States if they are given special permission from the USCIS and the money is not required to support you.
Your actions are limited to studying, working in addition to participate in the specific exchange visitor programs, which your visa has been approved.
You must first be acknowledged as a participant in an exchange visitor program, approved by the United States Department of State, previous applying for a J-1 visa.
Exchange visitors participating in specific types of programs could be required to go back to their home nation for at least two years before they are allowed to get a green card, change to another nonimmigrant status, or to have an L or H visa petition approved on their behalf.