Although I am quite comfortable using my PC, I stumble blindly through anything related to graphic images. I'd also like to know what the impact is when a graphic is converted from one form into another. When you save an image to a file that will be stored on your drive, pixels are translated into bits, the basic building block for storing information. When you get into saving images that have many shades of gray or lots and lots of colors, many more bits are required to save the information contained by one pixel. By default, in most cases when you save an image to a file, the program doing the work will format the file as a bitmap, or bmp, file.
Bitmap files use as many bits as they want in capturing an image.
In the late 1980s, when it became obvious that graphics were playing an increasing role in communications between computer users, experts developed the Graphical Interchange Format, or gif, which made it possible to compress graphics files and make them smaller. Gif files took up less space on the small drives of the times. Because they were smaller than conventional bitmaps they moved faster across phone lines. Gifs, though, cannot handle images that have more than 256 colors. Many images are made up of millions of colors.