Here are the 5 most commons visas

First, we’ll start with the Tourist visa (also known as a visitor visa). This grants you access to be a visitor/tourist in that country for a period of time. If you’re from the U.S., you will not need to do any up-front work to visit 174 different countries of the world. This is great news when there are 196 countries in the world. While it’s great Americans are able to enter so many countries without worry still make sure you do your research before you leave. 

2nd is the "Immigration and Naturalization” visas (including by marriage) Immigration visa is one that authorizes another person to permanently reside in a country. Though immigration does not necessarily suggest citizenship.
Next, you have the “Study Abroad” visa! If only we all were able to do this. A student visa is obtained when you are visiting a country for the purpose of an educational experience. These visas apply to exchange students of just a few weeks, or those staying a year or more. Requirements vary per visa and per country.

Then you have a “Business or Work” visa (for working, which includes both non-immigrant and immigrant types) is the strictest and most difficult to obtain in any country: the work visa. This is for a very simple reason: governments want economic activity in their country to be driven by their own citizens.

Last you have the new “Digital Nomad” visas are travel authorizations that legalize the status of workers on the move. Like tourist visas, they are easy to obtain. They allow long stays. The digital nomad visa allows its holder to work during their stay in the country, provided they do so independently and remotely. The worker must prove that he is a digital nomad and that he can financially support himself for the duration of his stay abroad. This can be done by providing financial documents such as account statements and invoices.