What are the visa & residency requirements in Saudi Arabia?

"In order to travel to Saudi Arabia, foreign nationals must apply for a visa and obtain authorization prior to arrival in the country. The process of applying for a visa includes submitting an application, including passport details and travel plans, to a Saudi Embassy or Consulate and providing documents that confirm the purpose of the visit, such as an invitation letter from a Saudi sponsor or an employment contract with a Saudi company. Foreign nationals who wish to reside in Saudi Arabia must obtain a residency permit, known as an Iqama. To apply for residency, applicants must first have a valid work or family visa and then submit all the necessary documents and fees at their local passport office. Applicants must also have a sponsor, who is usually the employer for work visa holders or a family member for family visa holders, who will be responsible for the visa holder's legal status in the country, as well as any necessary paperwork. After all the documents and fees have been submitted, the applicant will receive an Iqama card, which must be kept valid and renewed periodically," mentioned another expat when asked about moving to Saudi Arabia.