About PAT Files

• The PAT file extension is short for “Pattern.” In general, PAT files are square-shaped and are therefore frequently used to repeat in background images as tiles, enabling smaller file sizes that can then be repeated to fill a large space with a uniform texture. PAT files most frequently range from 8x8 pixels up to 256x256 pixels. Adobe Photoshop is the program most commonly associated with PAT usage.
  
  

About PNG Files

• The PNG file extension is short for “Portable Network Graphic.” It was created as a replacement file type for the formerly popular GIF image, with the intent of expanding the GIF’s rather limited palette of features. In general, PNG files are smaller in file size than GIFs of the same dimensions. PNGs also allow alpha transparency on more than one level, so that the opacity of different layers of the image can be varied. Gamma correction is also a feature of PNGs, allowing control over how the image looks on different platforms.
  
  

Pixels vs. Lines

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  Unlike GIFs, however, PNG files do not allow multiple images to be contained in a single file, thus limiting the popular animation feature of GIFs. The PNG also differs from the GIF in that it is rendered in pixels rather than in lines. This allows the contents of a PNG to become loaded progressively and therefore more visible to the user during rendering. PAT files are similar to PNG files in this way, in that they are also built with pixels.
  
  

PAT vs PNG

• In general, the major difference in utility between PNG and PAT files is that PAT files are more basic and mostly used to construct larger images. You would not get much use of a PAT file outside of the context of the image it is associated with. PNG files, on the other hand, carry more rich data and are useful for sharing full images that are self-contained with in the single file. Though each of these files can be used with a variety of software platforms, their purposes are distinct enough that they aren’t considered interchangeable.