A common misunderstanding is that vegetable oil comes from oily veggies. When really vegetable oil is the name typically given to any oil product that comes from a plant of any description (fruit, veggie, etc.). So oils like olive oil and sunflower seed oil are vegetable oils.
So is it good for you? Well, pure vegetable oils, such as olive oil, have been in use for thousand of years and their benefits to our diets are currently documented and understood. Vegetable oils are far better for you than animal oils.
The problem comes in when they are chemically altered, as hydrogenated vegetable oil (or partially hydrogenated) in the various forms like margarine, shortening and some liquid oils.
Check the ingredients for the chemically altered form.
Fit's Tip: A new trend in vegetable oil is to convert your car's gas tank so that you can run it on vegetable oil rather than gasoline.