Greenland's tax syestem is based on A and B taxes.
Salaries are in general A income. Fish trading to fish factories is also A income. The value of free goods offerd by an empolyer to employees is also A income.
B income include dividens, students support and incomes from private businesses.
A and B incomes have the same tax rates but different deductions.
On the Greenlandic and Danish page you can find a complete overview in the publication 'Tax rates in Greenland' and the supplemting list.