In essence, a Portuguese Work Visa is either a short-stay visa that allows you to work in Portugal for a time not exceeding 90 days or a temporary residence permit that allows you to work in Portugal for a time exceeding 3 months. A temporary residence permit can be renewed after 2 years for an additional 3 years. When you apply for a work visa, you will receive a residence permit which allows you to live and work in Portugal for one to two years. After 1-2 years, you can renew this permit at the SEF before it expires, as long as you still have a job offer from your employer.