The U.S. government requires students applying for F-1 international student status to demonstrate their ability to pay all tuition and living expenses in the U.S. without working (Graduate Assistantships or Fellowships are the only exceptions). That is why you are required to provide proof that you or your sponsor has such funding before MassArt will issue an I-20.
What is the definition of "work?" Work is anything you do for which you are compensated in any way. Some examples are obvious: If you get a job and receive paychecks, that is work. Others are less obvious: If you shovel a neighbor's sidewalk once after a snowstorm and they give you cash, that is work. If you help someone with a project and in return they give you free access to facilities that would normally require payment, that is work.
On-campus employment is permitted up to 20 hours per week while classes are in session. “On-campus” work means that you are being paid by MassArt, through MassArt’s payroll office (Graduate Assistant and Teaching Assistant positions are considered “on-campus” work).
Working without authorization, even just once, is a violation of your F-1 Student status. MassArt is required to report it to the U.S. government and penalties are severe.
Please find more information about on-campus employment opportunities here. After you arrive to MassArt, the International Education Center will provide additional information for F-1 students intending to work on-campus.
See the next question in this FAQ for information about off-campus employment.