What are the visa & residency requirements in Korea?

"In order to visit or stay in Korea, foreign nationals must obtain a visa from a Korean embassy or consulate. The process of applying for a visa involves submitting an application form, a valid passport, a passport-sized photograph, and other documents such as a bank statement or proof of employment. Depending on the purpose of the visit, additional documents may be required. In order to apply for residency in Korea, foreign nationals must submit an application form, a valid passport, a passport-sized photograph, and other documents such as a bank statement or proof of employment. Depending on the purpose of the residency, additional documents may be required. In addition, applicants must provide proof of financial stability, such as a bank statement or proof of employment. Once the application is approved, the applicant will receive a residence permit, which must be renewed every year," remarked another expat in Korea.