Resolution indicates the number of pixels (smallest area of an image) for each inch (25.4 mm), and is measured in dpi (dots per inch). The advantage of increasing the resolution is that the details in the image become fine. The disadvantage is that the file size becomes large.
File size becomes large
(When you double the resolution, the file size becomes about four times larger.)
Scanning, saving, and reading the image takes a long time
Sending and receiving emails or faxes takes a long time
The image becomes too large to fit the display or print on the paper