means to create a voucher for private schools. Many states have court decisions holding that no state funds can be paid to religious organizations. Many/most private schools are affiliated or sponsored by a church, so a direct voucher system doesn't work. Instead, in states that want to give vouchers for private schools, they allow you to donate to certain "charities." The "Charity" then makes a donation on your behalf to your private school, paying your tuition. In return, you get a tax credit (not a deduction) for the payment. It's just a voucher system for private schools with a couple of hoops to comply with state laws preventing tax funds going to religious entities.