Photoshop's "Buddy" Illustrator

[christopherm]

What does Illustrator do that Photoshop can't?

 

[joe_shmoe]

Illustrator is a vector-based postscript drawing program. It functions by generating curved paths (Bezier curves) connected by modifiable anchor points. These anchors, with their handles are ultimately editable, and never "leave" the structure of the file.
A vector based drawing program creates the various elements of the image as individual vector objects which retain their characteristics and do not become part of a "bitmap".
Fundamental difference: Illustrator generates "vector objects" which are not part of a "bitmap"