What is the difference between visa and work permit?

A visa is issued by the immigration authorities at the immigration office. An immigration official has the right to allow the person entry into the country. A work permit is issued by an international or national company that outsources in other countries for the sake of hiring professional staff.

While a visa is a document needed for entering a particular country, a work permit is an employment letter that is issued to an employee by an employer for the sake of entering the country.