What is the difference between fashion and casual modeling?

Answer 1

The main difference is that Fashion means that's your only job.
You may put in a 15 hour day of shooting and have to look just as glamorous, good, and cheerful in the last 15 minutes as you did in the first 5 minutes.
I think there is also a industry standard (or typical) minimum wage (which isn't too shabby - eve for a beginner).

You also are required to know how to do a runway walk, poses, understand the lingo, be able to change dresses in 60 seconds. travel anywhere on a moments notice from your agent (need one of those), & know everything there is to know about modeling.
The photographer's a pro - as well as the makeup,
hairdressers, lighting crew etc. The are also getting big bucks and if you make them waste time, kiss your career goodbye.

Casual modeling is something you do on the side or part-time.
Work out your own terms and pay (it you have to be told how to do every little thing - you'll get canned or not paid).
However, it's a good way to get experience to go pro.

That is, of course, assuming it's a legit deal. Which is maybe 5% of what you see.
There are tons of scams involving supposed modeling jobs, or teaching how to be a model, jobs they know about your perfect for, they have an inside contact - you name it.

Answer 2

A Fashion Model is a professional person whose job is to display clothing of whatever type for a design or fashion house to the buyers of a clothing or department store, or for a photographer for a magazine or catalog, or directly for the buying public. Their only job is to show the clothing off to its best advantage.
They may work as an independent or for an agency or for a designer or fashion house. They may specialize in photography such as ELLE or Vogue or the Penney's catalog or the Walmart newspaper ad. For every high priced well known model there are 10,000 men and women who make a living doing market week, trunk shows and catalog sales. They don't make much more than a secretary, if as much. And they have a very limited working life as old ladies and men don't get work.
Better they should do TV ads.
Casual modeling is anything from doing a few local shows a years to posing for the painting or sculpture class. Usually not paid, maybe get a lunch for it.