What is meant by the term 'Pixelated'?

The more pixels within an image, the bigger and better quality the file should be.

The term 'pixelated' is used to describe a poor quality image in which the pixels that your image is made up of are visible, especially when zooming in close.

A pixelated image will produce a poor-quality print which could be described as having jagged block'like edges instead of smooth lines.