Definition: a pictorial representation (as a photograph) of a person usually showing the face.
Are you quirky, cheerful, tall, short, punky, gothic, a wallflower, bookworm, nerd, athlete or dancer? Are you black, white, asian, oriental? Are you tattooed, pierced, be-spectacled or pregnant? Do you possess a face?
Portraiture is about capturing you and your personality on film, and in my opinion failing to look like a supermodel is a distinct advantage. The image could capture just one aspect of your personality or yourself as a whole.
There are many other reasons for wanting a few good headshots. A good looking picture on your blog pages or dating web-site is likely to bring more people back to your profile than a blurry snap taken the last time you were out on the town with friends. Alternatively you may want something for your business cards and letterheads or simply as a keep-sake for friends and family.
One of the nicest parts of this type of photography is the fact that the location and props usually choose themselves. All you need is the time and the energy. Where possible a stylist will be available to help with make-up, hair styling etc (if required).