What are the visa & residency requirements in Portugal?

"In order to enter Portugal as a non-resident, visitors must obtain a Schengen visa. Generally, Schengen visas allow short visits of up to 90 days within a 180 day period of time. Visitors who wish to stay longer must apply for a Residence Permit. The process of applying for a Schengen visa includes submitting an application, providing biometric information, paying the relevant fees, and attending an interview. In order to apply for residency in Portugal, applicants must first obtain a Residence Permit (unless the applicant is an EU citizen, in which case they can simply register as residents in Portugal). To apply for the permit, applicants must prove a legal source of income and submit a copy of a valid passport, two passport photos, and proof of address in Portugal. The process also includes an interview and a police record check. Once the permit is processed and issued, a residence card will be sent to the applicant's address," remarked another expat in Portugal.