it’s a program of temporary residence authorization in Portugal given to foreigners, who are not a part of the European Union, to develop economic activities and Investments Portuguese territory.

A physical person who wants to invest in Portugal but does not intend on spending more than 90 days in a 180 day period in Portugal does not require a golden visa;
However even if one does not intend on staying in Portugal, a physical person may always apply for a golden visa;
Receiving the golden Visa does not determine any fiscal implications to the requeree in Portugal.
Quite the contrary:

A physical person who has the intent of living in Portugal for fiscal effects and does not possess a European Union nationality, or an appropriate visa to live or eventually work in Portugal, must solicit a golden visa.
What are the main benefits of the golden visa?
The Golden Visa gives foreign investors the following benefits:

Possibility of entree and legal stay in Portugal without needing a residence visa.
Live and work in Portugal.
Move freely through the Schengen Zone, without needing a visa.
Benefits from family regrouping right – the owners of the golden visa may solicit the entry and residence of members of their family.
Eligible for a permanent residence authorization at the end of the 5 years.
Eligible to obtain Portuguese citizenship at the end of six years (so long as the owners of the golden visa have been living through this period in Portugal).
What kind of investments are allowed to obtain the golden visa?
Conditions for the golden visa

To be eligible, the investor must make, through a physical person (or through a “sociedade unipessoal portuguesa”), direct investment in Portugal, and maintain it for five years through one of the following options:

Capital transference of EUR 1.000.000.
Creating, at least, 10 work positions/jobs
Acquiring real estate assets in Portugal estimated at EUR 500.000:
One or more real estate properties, as long as the total value is EUR 500.000. The properties can be used for commercial, agricultural, or touristic purposes;
The acquired properties must be onerated (like a mortgage), but only corresponding to the part that exceeds, if so, the EUR 500.000 total;
The properties may be acquired in shared ownership, so long as each co-owner invests, at least, EUR 500.000 each.
Acquiring real estate properties in Portugal with +30 years, or located in an urban rehabilitation area being responsible for additional modernization work estimated at EUR 350.000.
Transferring EUR 500.000 by acquiring units in FIM or FCR for PME.
Applying EUR 350.000 in certain investigative activities.
Applying EUR 250.000 in certain activities which invest in artistic production, recovery, or maintenance of national cultural patrimony.
Except for cases (I) and (V), the minimum amount demanded may be reduced by 20% in certain conditions foreseen by the law.

What are the conditions an investor must meet?
The golden visa presents a very low number of conditions investors must meet. The program determines that the investor must be under all the general conditions applied to every kind of qualified investments and also with the specific need of every kind of investment.

Every investor must meet the following conditions:

Maintain the investment for at least 5 years
The investments must come from abroad
Enter Portugal with a valid Schengen visa
Absence of reference in the Portuguese Immigration Service and Schengen Zone services
Absence of condemnations in relevant crimes
Minimum stay in Portugal: 7 days in the first year and 14 days for every period after the second year
How long is the golden visa valid for?
Once emitted, the golden visa will be valid for one year, and then will be renewed for the following two-year periods.

Is it possible to extend the golden visa to family members?
Yes. The investors’ families may ask for a residence authorization in Portugal, arguing “family reunion”. The golden visa will be extended to close family members: children, spouses, and family members who depend on the original owner of the visa.

The family members are equally eligible to obtain permanent residence after 5 years and Portuguese nationality after 6 years.

How can the investors and their families obtain the permanent residence authorization after the 5 years?
According to Portuguese Law, any person with a temporary residence title (such as the golden visa), valid for at least five years, has the right to apply for permanent residence in the country.

To do so, the investors’ and their families must meet the following conditions:

Absence of relevant criminal condemnation in the past five years
Income/financial independence proof
Housing proof in Portugal
Basic knowledge of the Portuguese language
How can the investors and their families obtain Portuguese nationality?
The Portuguese legislation establishes that any person who has lived legally in Portugal for at least six years (through a temporary residence title or a permanent residence title) is eligible for obtaining Portuguese nationality.

For that to happen, the investors’ and their families must meet the following criteria:

Absence of any relevant crime condemnation
Be at least 18 years old (or 16, if married or legally emancipated)
Pass at a simple Portuguese language test, which serves to show sufficient knowledge of the language