A uniform Schengen visa allows third-country nationals subject to visa requirement to enter or transit through the territory of every country composing the Schengen area. Such visas are referred to as uniform in view of the fact that the respective regulation is common to all Convention Implementing the Shengen Agreement (CISA) Member States. They are aimed at intended short-term stays in the territory of the Member States with a duration of no more than three months and are usually conferred for purposes of tourism.
A long stay visa is regulated in the framework of the existing national legislation and may be either for temporary stays or for residence, according to the length of the stay. Such visas allow their holder to remain in Portugal for the intended purpose: e. g. study, internship, work or medical treatment.
In general, a temporary stay visa is valid for 4 months and multiple entries.
A residence visa is usually valid for 2 entries and 4 months, after which its holder must have obtained a residence permit.