Every artwork must be shown in some physical place, if it is to be seen at all. That place could be a gallery, a museum, or a living room. And of course, it could be on a computer monitor as well.
How does an individual artwork fit in the physical place where it is exhibited? The fit might be poor, but the artist usually has limited control of where his or her artwork will be shown. The frame is the practical solution to this problem. A frame provides a local context for an artwork, which to some degree can isolate it from its surroundings. A well-chosen frame will enhance the best qualities of the artwork, and protect it from being overwhelmed by what is around it. Good frames are difficult to find.

Exhibiting art on the internet does not take away the importance of the frame, but the nature of the frame is altered. The web-page itself acts as a frame for an artwork on the internet — the layout of the page, the font, the color of the text, these take the place of wood, carving, and gilding of a normal picture frame. Thus even if an artwork is shown on a web-page without a “normal” frame, it still has a framing context which surrounds it wherever the web-page is viewed.

_________
Related:
Internet as Frame part II, Minimalism
Fall of the Art World