In an effort to have pages look their best, Web authors often created several versions of their pages with workarounds to compensate for these differences between browsers. The latest generation of Web browsers does away with almost all of these discrepancies in the way they interpret Web data thanks to the W3C standards. However, many Web pages are still designed for the old behavior of browsers. With the introduction of the latest generation of Web browsers, pages are gradually being redesigned to fully comply with the latest standards. Computer displays are divided into tiny squares called pixels.
Larger monitors have more surface area and therefore more pixels.
Likewise, higher quality displays, including those on modern laptops, often display more dots per inch, resulting in sharper images. As the resolution, or pixel density, increases, the number of pixels or dots per inch increases. Take a look at the two inches below one designed for 72 dots per inch and the other designed for 96 dots per inch. Hold a ruler to the screen, an inch should approximately look like one of the two lines below.