Technically, this is making a vector shape and not a "true vector." True vectors you can zoom in on the fly and not get a pixelly looking image. (This concept is used in works created by programs like Adobe Illustrator). In Photoshop, this is called a vector mask. For the most part, nobody really cares which program you use, but some suicidial extremists (and the uneducated) will say that Photoshop does not produce vectors. They are wrong.
