This list of visas will explain the primary purpose of each type of visa you may obtain in order to visit Vietnam.
Tourist visa
The tourist visa is the most popular type of visa, and it is fairly easy for all nationalities to obtain. There are basically two types of tourist visas, divided into 30-day single or multiple entry. However, it is fairly easy to obtain a 3 month business visa if you’re planning to spend longer in the country and don't want to cut your trip short. Note that there will be a price difference according to whether it is a single or multiple entry visa.
Tourist visa extension
Tourist visas may be extended only once for 30 days. Although it would save some money, it can be quite a hassle to do the application on your own, so it is recommended that you spend the extra money and do the process through a tour agency. It should only take two or three days, and is easiest in the bigger cities, such as Ho Chi Minh City, Hanoi, Danang and Hue.
Re-entry visa
If you arrive in Vietnam with a single entry visa, then decide that you want to travel to a bordering country, and later return to Vietnam, you must have a re-entry visa. Arrange it before you leave Vietnam, otherwise, you will have to go through the entire visa process again. It is best to do this through a travel agent, as you will most likely need help with the paperwork, and they can complete the procedure in a day or two.
Business visa
A business visa allows entry for the purpose of work. They are usually valid for three to six months. In general, business visas are easy to get, but there may be a significant difference in price versus a tourist visa. Note that a business visa is not a work permit - it only allows entry for the purpose of work. In order to work in Vietnam, you must have a work permit.
Student visa
You may request a student visa once you have received admission evidence from a school in Vietnam (pre-departure), but usually student visas are arranged after arrival in Vietnam. You may enter on a tourist visa, enroll in a program of study (language courses apply), then change the status of your visa with immigration. It is best to have a travel agency help with the application process.
Transit visa
The maximum duration for a transit visa is five days. The Department of Immigration will generally issue transit visas only for groups accompanied by a tour guide. The group must have an exact itinerary and a guarantee from a tour agency that is organizing the tour.
Diplomatic and official visa
These visas are granted to those visiting Vietnam on government or diplomatic business, and there is no fee associated with this visa. The applicant for this visa must submit an official letter (note verbale) from the concerned agencies of local government, foreign embassies or consulates accredited to the applicant's country, international organizations or other accredited organizations based in that country.