People who want to buy a digital camera need to understand what resolution is because it is this term that decides the quality of an image. They also need to understand what pixel is because the resolution of an image is expressed in terms of pixels per inch and that of a digital camera in terms of megapixels.
The term pixel itself is derived from the words “picture element" and is used to refer to the smallest dot in an image that is used to store color. A picture is said to have good resolution if it is packed with dots or pixels over every inch of the image. This metric is also referred to as pixels per inch or ppi.
One million pixels go to make a megapixel, and a camera that shoots a picture that has one million pixels is said to have a resolution of 1MP or one megapixel. Similarly a camera that can shoot a picture that has five million pixels on its surface is said to have a resolution of 5 megapixels. A higher resolution camera therefore provides better picture quality. That is why professional photographers use cameras whose resolution ranges from 14MP to 22 MP. These photographs are not only sharp and clear but also print well. They can also be easily enlarged without losing sharpness or focus.
In contrast, it is difficult to improve the quality of low resolution images. The photographers are forced to add pixels through a process known as interpolation. In this process, an intermediate color is assigned to the added pixels, which is based on the color of the existing pixels. This process can add to the resolution, but not to clarity. The reason for this is that you cannot create something from nothing.
Interpolation is a common feature on low-priced, entry level digital cameras. The lower the actual resolution of the image, the lower the clarity of the interpolated image will be. Usually a 3.2 megapixel digital camera will provide images with sufficient resolution for general photography. However, if you are into more serious photography you will need a camera with a higher resolution.
Fortunately, this problem does not exist on the Internet. Web designers keep the resolution of images at 72 ppi that is 72 pixels per inch. This produces a sharp image on a computer screen. Also, the picture download is fast because the picture is not weighed down by the weight of pixels.