[Colquhoun]

When you work in Photoshop, it might be vector, but it all depends on how you save the file. If you leave it as a .psd file with the text layers not rasterized...then yes, it is vector. But you cannot take an image, add text, save it to a jpg on a website, and then expect to later enlarge the image without the text looking jaggy. So, have a working .psd file...and save in different formats for distribution.