Jaggies
From The Glossary of Digital Photography
Also known as aliasing artifacts. The stair-step-shaped artifacts seen instead of straight or curved lines. Jaggies are often caused by increasing the resolution (uprezzing) of an image more than the original resolution will permit. A software technique called anti-aliasing can be used to smooth the jaggies where possible. Other smoothing functions are also available. The jagged edges are actually individual pixels or small groups of pixels. Increasing the real resolution of an image by creating a higher-resolution original at the time of photography is the best way to prevent this problem.
Jaggies are most noticeable on diagonal and curved lines.
