Being a W-2 employee means that you are officially employed by Raise on assignment with College Board, and as such, taxes and other payroll deductions will be automatically withheld from your paycheck.
This simplifies your tax filing process since the deductions for federal, state, and possibly local taxes, along with Social Security and Medicare, are taken care of for you.
As a W-2 employee, you will need to fill out a W-4 Federal Tax Form and any relevant state tax forms to ensure the correct amount is withheld from your pay.