Here is a fast overview for both types of travel visas.
First either one is only good for 21 days. Here is how to obtain a business visa:
Simply complete the visa application we provide and include a passport type photo. You will need to have a passport with an expiration date of at least six months beyond the completion date of your trip to Armenia and your passport must have one blank visa page. If you need to renew your passport or add pages, let our agent know as we can help you with that too.
Business travelers will need to provide a company business letter (we can help you with that) and a flight itinerary.
The requirements for obtaining a tourist visa are the same except you will not need to provide a company letter.
You can read exactly how to get your travel visa for Armenia here.