Resolutions
Resolution is the number of dots available to represent graphic detail in a given area: on a computer screen, it's the number of dots or pixels per linear inch (ppi); on an output device, it's the number of dots printed in a linear inch (dpi); on a scanner, it's the number of pixels sampled per linear inch of the scanned image. The resolution of an output device influences both the clarity of detail and the tonal range that can be reproduced from bitmap images.
A pixel is the smallest distinct unit of a bitmap image. A high-resolution bitmap image contains enough data – a description of each pixel's location and what colour is displayed - to show more detail in the image. A low-resolution image doesn't have as much data to render the same level of detail.
A high bitmap resolution doesn't always produce a better printed image. A bitmap image may contain more data than an output device can represent; therefore it is important to determine the appropriate bitmap image resolution to achieve the best printed image. If the image resolution is too high for an output device, it will take a long time to image: if the image resolution is too low, the quality of the output will be poor.
