A vector graphics editor ... The preferred software for Illustrators and Graphic Artists. You can scale the artwork to any size (from business card to full scale billboards) without sacrificing the resolution.
Raster vs. Vector
a really good (short) video explaining the difference ...
Introduction to Illustrator
- Scalable Art
- Crisp/Sharp lines
- Print Hi-Resolution
- Smaller file size
- Good for drawing illustrations
- Drawings look flat (cartoon like)
- Photo-realism is not usually possible