Photoshop is a high-end graphics software package used to manipulate photos and images. It is also used for file conversion. You can convert your TIFs, PCXs, PICTs, etc. (uncompressed file formats) into browser ready JPGs and GIFs (compressed file formats)!!!! Along with Photoshop's file conversion options is the ability to adjust resolution, file size, and physical size. All of these are very important when working with images and text graphics for the Web.

At the left is the Photoshop Toolbar. Below is the Image Size dialog box. In this area you can specify the physical size of your image and the resolution. Seventy-two pixels/inch (72 ppi) is the resolution you want to use for all of your images on the Web!

JPG vs. Gif
RGB vs. Indexed Color

The dialog box at the right is part of the "Save for Web" choice under File in the upper menu area of Photoshop. In this case, the menu displays the characteristics of a GIF constrained to a color palette of 32 colors. You can see all 32 color variations displayed in the Color Table tab in the lower portion. The range of blues that you see in this "palette" refer to the blues in the title bar of the Image Size dialog box above right. Notice the color banding that resulted from constraining the color palette.