Photoshop Expert Question:

Photoshop CS2 introduces a new type of layer called a Smart Object layer. Smart Objects are a little like symbols in Illustrator. Smart objects can consist of pixel-based content or vector-based content, like an Illustrator drawing placed in a Photoshop document. With smart objects, you can make multiple copies of a single object and all copies will be updated when one of the copies is edited ? but you can still apply layer styles and adjustment layers to the individual smart objects without affecting all copies, which provides for a lot of flexibility. Pixel-based smart objects also remember their original size and can be transformed multiple times without loss.
Smart objects is the pixel-and vector based content.