To enter South Korea, you generally need a passport and either entry visas, or an approved Korea Electronic Travel Authorization (K-ETA) if your country is on the visa-exempt list. For non-visa-exempt countries or purposes other than tourism (e.g., work, study), a proper visa from the nearest Korean embassy or consulate is required. Nationals from visa-exempt countries can apply for a K-ETA online for stays up to 30-60 days. 

For Visa-Exempt Countries (with K-ETA):

1. Confirm Eligibility: Check if your country is on the K-ETA eligible list. 
2. Apply for K-ETA: Obtain K-ETA approval online at least 72 hours before your flight. This electronic travel authorization is valid for two years. 
3. Entry: You will be exempted from submitting an arrival card upon entry. 

For Non-Visa-Exempt Countries:

1. Determine Purpose of Visit: 
   Identify the specific visa category needed (e.g., tourism, business, education, employment). 
2. Contact Embassy/Consulate: 
   Find the nearest Korean embassy or consulate in your country. 
3. Gather Documents: 
   Collect necessary documents, which typically include a completed application form, valid passport, passport-sized photos, travel itinerary, financial proof, and other supporting documents relevant to your visa type. 
4. Apply for Visa: 
   Submit your application through the designated channels, which may involve visiting the embassy or using an appointed travel agency or courier service. 

Important Considerations:

• Purpose Matters: K-ETA is for tourism and social visits. For work, study, or other specific purposes, you must apply for a formal visa. 
• K-ETA is Not a Visa: K-ETA is a travel permit for visa-exempt nationals, not a visa itself. 
• Application Timing: Apply for K-ETA well in advance of your travel date. 
• Stay Informed: Visa policies and requirements can change, so always check the official Visit Seoul or Korea Visa Portal for the latest information before your trip.