When someone say portrait, studio, or vertical type of photo comes to mind. I live portraits! Love to take portraits of my children, Liza, my wife and whoever I can shoot! Portraiture photography is special because it can really bring out the character in you.
Portraits can be taken both in lanscape and verticle. Someone use the term portrait as verticle shot only. That is not true. When I shoot animals, that can be portraits too. Headshot, shoulder length shot, side profile shot are some of the portraits you can do. To take a portrait, you don't have to do it in a studio, or even have special lighting system. You can do it anywhere with enough lights.
Best portraits are taken in the evening. The reflection of the lights coming in thru the window work wonders! Studio lighting try to simulate this and it takes hours just to get it right.