What are the visa & residency requirements in Qatar?

"In order to visit Qatar, foreign nationals must obtain a visa prior to arrival. The process of applying for a visa involves submitting an application form, a valid passport, and a passport-sized photograph. Depending on the purpose of the visit, additional documents may be required. In order to obtain residency in Qatar, foreign nationals must obtain a residence permit. The process of applying for a residence permit involves submitting an application form, a valid passport, a passport-sized photograph, and proof of employment or sponsorship. Additional documents may be required depending on the purpose of the residency," mentioned another expat when asked about moving to Qatar.