There is nothing more fundamental to the practice of digital art than the smallest unit of separation on the screen: the pixel. While one avenue of digital art seeks to minimize the pixel's presence (the struggle to continually create higher and higher-resolution displays) there is a different kind of practice that draws attention to the tiny graphic unit. Take the sculptural art of Shawn Smith, whose 3D works are so dependent on the notion of the pixel that, when viewed from the front, they appear to flatten into 2D objects.
On the Web, the pixel is a different material, capable of drawing attention to certain aspects of a work that demands more and more "quality" out of computer displays. We are all familiar with the look and feel of 8-bit video games, and many some artists continue to play with that aesthetic. Take the work of Rod Hunt, whose pixel placement game is so on point it's almost unbelievable. This is painstaking work.