Denmark has a welfare system that is financed through taxes. Taxes finance, e.g. health and medical services, childcare, education, care of the elderly, infrastructure, etc. You must contact the authorities to receive a tax rate and deduction card.
Coming to work or live
You must inform SKAT, the national tax authority, when you come to Denmark to work or live. Even though you may not work in Denmark, you may still be required to pay taxes.
Coming to study
As a student in Denmark, you must pay tax on your income if you earn over a specific amount. For that reason, you will need a tax rate and deduction card.
When you leave Denmark, you must notify the Danish tax authorities.